Work lost when switching between models

[robosoup2]

after painting the textures on a helmet mesh, i spent an hour painting textures on body armor, and when i left "backslash" mode I found the textures on the helmet had been reverted to an early state; specifically, all brush strokes were gone, except for a few i'd done before fixing a certain UV problem.

I had lost some work earlier in the helmet painting process too, but it was only a few strokes so i didn't think much of it at the time. I've been saving often but not in Increments so the work is lost.

I can't confirm for sure that "Switching between models" is the cause, I don't know how to reproduce reliably, but I swear there is no user error I can imagine causing this

on blender version 4.1