Using BetterTouch, I made "CMD + Shift + S" the shortcut trigger to launch Slack.
After realizing it overrode tons of native shortcuts in other apps (ex: "save as", share screen in Zoom, etc), I deleted the shortcut in BetterTouch, but it didn't remove the overriding.
Instead, everytime I press the shortcut, a star symbol flashed on the screen (pic below).
What I've tried
across all below steps, recreate workflow with this shortcut and delete them
updated from Mojave to Ventura
uninstall and reinstall BetterTouch
restart the machine
exploring BetterTouch file system
Please help
Affected input device (e.g. MacBook Trackpad, Magic Mouse/Trackpad, Touch Bar, etc.):
MacBook Keyboard and Magic Keyboard
the star symbol seems to be a "SF Symbol" icon which is shown inside of a BTT "HUD" overlay. You have probably configured that to show when the trigger is executed.
This means you still have the cmd+shift+s trigger configured somewhere in BTT. Are you sure you checked all your configured Shortcuts for all apps you have configured in BTT?
The fishy thing is that this symbol appears even when BTT is uninstalled. Note that I uninstalled it twice, and picked "uninstall completely" each time.
It's not an icon file, it is part of Apple's SF Symbols font. So you won't be able to search for it.
Did I understand correctly, this does happen while BTT is quit? If so that would mean it's not caused by BTT. However as it very much looks like a BTT HUD that would be quite weird. Can you check via Activity Monitor to make sure you have really quit any BetterTouchTool instances?
in that case what you are seeing is not caused by BetterTouchTool. Maybe Apple's Shortcutsapp can do similar overlays and you have configured it there?
Otherwise I would try to quit app after app to see which one causes this.