So, I had this issue a few times, and I can't really pin point the exact scenario, but it more or less looks like this:
I use clone or healing tools (maybe inpainting tool too), extensively, to fix some areas of the photo (usually larger ones), while doing this, I think, I use undo (ctrl+z) a bit too.
What I get is that sometimes parts of my work disappear, like the layer gets cleaned, at least in part, in the offscreen parts (I work zoomed in). There is nothing in history that shows what could have happened, and going back I can see a lot of entries, but it's like glitching a bit when sliding all the way to beginning of history and I can see parts of my work being removed and applied with each history step. Unfortunately last time I could not record this but I will try to do this. I'm also writing this to check if anyone else has had similar issues with latest releases?