🐞 Does not work correctly with Karabiner-Elements

[Caffeine19]

Bug Description

I am using Loop together with Karabiner-Elements to remap key combinations.

My setup is:
1. In Loop, I set right_control + left_command as the trigger key.
2. In Loop, I set right_control + left_command + left_option + left_shift + space to maximize window.
3. In Karabiner-Elements, I remap:control + command + space → command + right_control + option + shift + space

So in practice:
• When I press control + command + space, it gets remapped by Karabiner to command + right_control + option + shift + space, which should trigger maximize in Loop.

This setup used to work correctly, but after an update and a restart a few hours ago, it stopped working.

This is my rule in Karabiner:

{
  "description": "Command + Control + Space to Hyper Space",
  "manipulators": [
    {
      "type": "basic",
      "from": {
        "key_code": "spacebar",
        "modifiers": {
          "mandatory": ["command", "control"],
          "optional": ["any"]
        }
      },
      "to": [
        {
          "key_code": "spacebar",
          "modifiers": ["command", "right_control", "option", "shift"]
        }
      ]
    }
  ]
}

This is my Loop config:

{
  "actions" : [
    {
      "direction" : "BottomLeftQuarter",
      "keybind" : [
        4,
        38
      ]
    },
    {
      "direction" : "BottomRightQuarter",
      "keybind" : [
        37,
        38
      ]
    },
    {
      "direction" : "Center",
      "keybind" : [
        36
      ]
    },
    {
      "cycle" : [
        {
          "direction" : "BottomHalf",
          "keybind" : [

          ]
        },
        {
          "direction" : "BottomThird",
          "keybind" : [

          ]
        },
        {
          "direction" : "BottomTwoThirds",
          "keybind" : [

          ]
        }
      ],
      "direction" : "Cycle",
      "keybind" : [
        38
      ],
      "name" : "Bottom Cycle"
    },
    {
      "cycle" : [
        {
          "direction" : "LeftHalf",
          "keybind" : [

          ]
        },
        {
          "direction" : "LeftThird",
          "keybind" : [

          ]
        },
        {
          "direction" : "LeftTwoThirds",
          "keybind" : [

          ]
        }
      ],
      "direction" : "Cycle",
      "keybind" : [
        4
      ],
      "name" : "Left Cycle"
    },
    {
      "cycle" : [
        {
          "direction" : "RightHalf",
          "keybind" : [

          ]
        },
        {
          "direction" : "RightThird",
          "keybind" : [

          ]
        },
        {
          "direction" : "RightTwoThirds",
          "keybind" : [

          ]
        }
      ],
      "direction" : "Cycle",
      "keybind" : [
        37
      ],
      "name" : "Right Cycle"
    },
    {
      "cycle" : [
        {
          "direction" : "TopHalf",
          "keybind" : [

          ]
        },
        {
          "direction" : "TopThird",
          "keybind" : [

          ]
        },
        {
          "direction" : "TopTwoThirds",
          "keybind" : [

          ]
        }
      ],
      "direction" : "Cycle",
      "keybind" : [
        40
      ],
      "name" : "Top Cycle"
    },
    {
      "direction" : "Maximize",
      "keybind" : [
        49,
        56,
        58
      ]
    },
    {
      "direction" : "NextScreen",
      "keybind" : [
        30
      ]
    },
    {
      "direction" : "PreviousScreen",
      "keybind" : [
        33
      ]
    },
    {
      "direction" : "TopLeftQuarter",
      "keybind" : [
        4,
        40
      ]
    },
    {
      "direction" : "TopRightQuarter",
      "keybind" : [
        37,
        40
      ]
    }
  ],
  "triggerKey" : [
    55,
    62
  ],
  "version" : "🧪 1.4.0"
}

Steps To Reproduce

1.	Set right_control + left_command as the trigger key in Loop.
2.	Set right_control + left_command + left_option + left_shift + space to maximize in Loop.
3.	In Karabiner-Elements, remap: control + command + space → right_control + command + option + shift + space
4.	Press control + command + space on the keyboard.

Expected Behavior

The window should be maximized.

Actual Behavior

The maximize action is triggered, but the window is not actually maximized.
The Loop preview window briefly becomes maximized and then changes to a smaller size.

Screenshots

Recording.at.2026-01-05.16.41.58.mp4

macOS Version

macOS 15.7.3

Loop Version

Version 🧪 1.4.0 (1631)

Additional Context

Recording.at.2026-01-05.16.41.58.mp4

Final Checks

• My issue is written in English
• My issue title is descriptive
• This is a single bug (multiple bugs should be reported individually)
• I can help with fixing or developing this issue (tick if you can help).

[Caffeine19]

The key remapping works correctly in Karabiner-EventViewer.

Additionally, if I press command + right_control + shift + option + space directly,
without using Karabiner, it also works as expected.

[Caffeine19]

I did some more testing, and it seems
in the ( command + control ) + ( shift + space)
The (shift + space) cant be correctly handled when mapping from Karabiner
if I set (command + control) + (space)
and map from Karabiner was handled correctly

1. work, space only

Loop:

Karabiner Rule:

{
  "description": "Command + 1 to Maximize",
  "manipulators": [
    {
      "type": "basic",
      "from": {
        "key_code": "1",
        "modifiers": {
          "mandatory": ["command"],
          "optional": ["caps_lock"]
        }
      },
      "to": [
        {
          "key_code": "spacebar",
          "modifiers": ["command", "right_control"]
        }
      ]
    }
  ]
}

2. failed, space + shift

Loop:

Karabiner Rule:

{
  "description": "Command + 1 to Maximize",
  "manipulators": [
    {
      "type": "basic",
      "from": {
        "key_code": "1",
        "modifiers": {
          "mandatory": ["command"],
          "optional": ["caps_lock"]
        }
      },
      "to": [
        {
          "key_code": "spacebar",
          "modifiers": ["command", "right_control"]
        }
      ]
    }
  ]
}

[Caffeine19]

I had to use "space + additional modifiers" instead of just "space",
because "command + control + space" opens the macOS emoji picker
in some apps such as Warp and Zed.

Loop does respond to this shortcut and the trigger is fired,
but the event is not swallowed or stopped, so it is still handled
by the system or the application.

warpdotdev/warp#6486
zed-industries/zed#30932

[SenpaiHunters]

Have you set your keybinds to require a double-click to activate, or anything that stops the loop from activating for a second? Although I want to note that our focused development is on the app itself, not on another app used to trigger the bind, as we cannot replicate it or will need to exceed time to test and work on features. It may be a macOS limitation, as I can see the preview is activating.

Do me a favour and go to Console (the macOS app), start recording a session, and in the top right-hand side, enter com.MrKai77.Loop. Then do the same keybind and paste in the result it gives below. You can bulk copy by ⌘A + ⌘C, then ⌘V into the upload, or as a separate text file, and upload it that way. This will help us find if there is something incorrect inside Loop or if it's solely related to Karabiner Elements/macOS.

[Caffeine19]

Thanks, I didn't set the delay or press twice:

I pressed the hotkey (command + control + space) and mapped by Karabiner to (command + control) + (option + shift + space) once, and this is the log I got:

default	23:33:15.970447+0800	Loop	2026-01-05 23:33:15.970+0800 🎨 [PreviewController] Set action to 'WindowAction(direction: NoSelection, name: No Action)'
default	23:33:15.986208+0800	Loop	2026-01-05 23:33:15.986+0800 🎨 [PreviewController] Set action to 'WindowAction(direction: NoSelection, name: No Action)'
default	23:33:15.986479+0800	Loop	2026-01-05 23:33:15.986+0800 🎨 [RadialMenuController] Set action to 'WindowAction(direction: NoSelection, name: No Action)'
default	23:33:16.320552+0800	Loop	2026-01-05 23:33:16.321+0800 🎨 [PreviewController] Set action to 'WindowAction(direction: Maximize, name: Maximize)'
default	23:33:16.320576+0800	Loop	2026-01-05 23:33:16.321+0800 🎨 [RadialMenuController] Set action to 'WindowAction(direction: Maximize, name: Maximize)'
default	23:33:16.598473+0800	Loop	2026-01-05 23:33:16.598+0800 🎨 [RadialMenuController] Set action to 'WindowAction(direction: NoSelection, name: No Action)'

Another try:

default	00:40:59.934679+0800	Loop	2026-01-06 00:40:59.935+0800 🎨 [PreviewController] Set action to 'WindowAction(direction: Maximize, name: Maximize)'
default	00:40:59.940623+0800	Loop	2026-01-06 00:40:59.941+0800 🎨 [PreviewController] Set action to 'WindowAction(direction: Maximize, name: Maximize)'
default	00:40:59.940737+0800	Loop	2026-01-06 00:40:59.941+0800 🎨 [RadialMenuController] Set action to 'WindowAction(direction: Maximize, name: Maximize)'
default	00:41:00.142939+0800	Loop	2026-01-06 00:41:00.143+0800 🎨 [RadialMenuController] Set action to 'WindowAction(direction: NoSelection, name: No Action)'

And this is I press (command + control) + (option + shift +space) without karabiner:

default	00:13:34.012454+0800	Loop	2026-01-06 00:13:34.012+0800 🎨 [PreviewController] Set action to 'WindowAction(direction: Maximize, name: Maximize)'
default	00:13:34.018906+0800	Loop	2026-01-06 00:13:34.019+0800 🎨 [PreviewController] Set action to 'WindowAction(direction: Maximize, name: Maximize)'
default	00:13:34.018980+0800	Loop	2026-01-06 00:13:34.019+0800 🎨 [RadialMenuController] Set action to 'WindowAction(direction: Maximize, name: Maximize)'

[Caffeine19]

I also update the loop version on my another mac, the previous 1610 version works fine, it failed in in 1631 version

[mrkai77]

Thanks for the helpful info, @Caffeine19! This bug should now be fixed at: https://github.com/MrKai77/Loop/actions/runs/20731403055/artifacts/5030533604
Would you mind testing it and letting us know if it’s resolved?

[Caffeine19]

Thanks for the helpful info, @Caffeine19! This bug should now be fixed at: https://github.com/MrKai77/Loop/actions/runs/20731403055/artifacts/5030533604 Would you mind testing it and letting us know if it’s resolved?

It's totally fixed now! Really thanks to you! 😘

In the console:

default 09:24:37.717276+0800 Loop 2026-01-06 09:24:37.717+0800 🎨 [PreviewController] Set action to 'WindowAction(direction: Maximize, name: Maximize)'
default 09:24:37.721129+0800 Loop 2026-01-06 09:24:37.721+0800 🎨 [PreviewController] Set action to 'WindowAction(direction: Maximize, name: Maximize)'
default 09:24:37.721353+0800 Loop 2026-01-06 09:24:37.721+0800 🎨 [RadialMenuController] Set action to 'WindowAction(direction: Maximize, name: Maximize)'