@sugarfree I tried Bookworm 32 again recently with a Pi3b+ and still had the GPU Reset issue.
It seemed to mask it for a bit, but eventually still leads to the visible GPU Reset issue.
Every Bookworm flavor OS I've tried actually I continue to have the issue.
So far, the only OS with Full KMS on Pi3b+ (newer than Buster) I tried that did not have the GPU Reset issue is Armbian Ubuntu 24.04 (Noble).

Edit: Nevermind, it happens on Armbian Ubuntu Noble too.