Possible modifier-stuck-down issue on Big Sur

Describe the bug

Just updated to Big Sur. Every 5 minutes or so, it seems a modifier is stuck down, as certain shortcuts stop working and others get triggered when not intended. I believe it is usually the fn key getting stuck down based on the shortcuts getting triggered, but it happens suddenly and is intrusive, so I always restart BTT rather than experimenting. (This just happened again and it didn't seem to be fn this time as it didn't affect my function row keys, but I'm fairly certain it was fn previously.)

Affected input device

Device information:

  • Type of Mac: MacBook Pro (13-inch, 2017, Two Thunderbolt 3 ports)
  • macOS version: 11.1
  • BetterTouchTool version: 3.543

You seem to be on the current alpha version of BTT. I'd recommend to go back to the latest stable release ( https://folivora.ai/releases/btt3.540-1679.zip ) as the alphas currently contain a few untested changes related to modifier keys (although I haven't experienced issues yet).

If that doesn't help try to go through your presets and check whether you have any modifier key actions that might trigger a key down but not a up event:

Thank you, @Andreas_Hegenberg, for this unbelievably quick response! I have downgraded and turned off alpha channel updates. If the problem persists, I will post a reply here.

As always, this tool is the #1 reason I do not switch to a Linux machine and I hugely appreciate your work.

This seems to have fixed the bug. It was happening every 2-5 minutes, and after downgrading it hasn't happened for over 20 minutes. I guess that's what alpha versions are for! I hope you figure out what was going wrong. If I can help in any way please let me know.

If you have some time it would be great if you'd check the latest alpha version. I hope this issue is fixed