Thanks again for the feedback.
What image version does your machine report? (Bottom left of of screen). I can't share you my image as it is the master dev image with all the src code on it :-) Though I also could not reproduce this on my A1200NG image. (version V14) I wrote a looping script to change floppies every10s and got no lockups after 150 or more loops. This script interacts directly with amiberry so doesn't actually open the pause window, but I don't think that should affect it as I also toggled that a goof few times as well.
This one is a bit of a mystery at present.
Ironically found an unrelated bug whilst testing this, (closing the choosedisk window via the joypad start button would it to crash next you opened from the pause menu) so that be fixed in next update. This was not this bug though as that caused segfault in the A600GS main menu not amiberry, which happily keeps running by itself in that case.
Amiberry-Lite 5.8.7 / PatchLevel 65 (2025-04-17)
I was using a slghty older version and newer rebuild that src base, but even after forcing that exact version I get no issue, weird