Hi, thanks so much for your quick response!
I've now tried a few other launchers: Nova7, AIO Launcher, Microsoft Launcher and Smart Launcher
Unfortunately the black flicker behaviour still persists.
(Indeed, the black flicker does NOT occur on the lockscreen where I think the launcher isn't responsible)
Any more suggestions would be much appreciated!
Just for reference, I'm on a Samsung Galaxy S23, One UI 5.1, Android 13
I imagine this is quite a common setup - perhaps others have experienced the same?