Hyperkey "open URL" to Keyboard Maestro causes app windows to flicker

I've noticed a very brief flicker in any app window when I use the BTT hyperkey to send an "open URL" action to Keyboard Maestro. I see it particularly in the window's top toolbars, clickable items in inspector panes and in the window's drop shadow.

It doesn't happen with a BTT hyperkey that's not sending a URL to Keyboard Maestro.

Any idea what's causing this with BTT, or how to stop it? With clickable items flashing, could it have something to do with accessibility features?


After further study, I've found it's NOT a BTT problem. It happens when any app sends an "open url" command to Keyboard Maestro.

I'll check with the Keyboard Maestro forum!

AND, if anyone can tell me how to delete a topic that's no longer relevant, please do so!