Users have reported rotating assets don’t always force-invalidate the thumbnail or fullscreen preview to show the new, correct orientation.
Hitting reload (f5 or ctrl-r) should show the correct orientation (as a hacky workaround until this bug is fixed).
I ran into this bug, and reload didn’t work. The first time, I did a force reload and it didn’t fix it. So I exited and restarted PhotoStructure and it fixed it. The 2nd time, I tried a force reload and then did the exit/restart - now the asset is completely gone from my PhotoStructure library. (original file remains though, no source data was lost).
Thanks for reporting.
I’ll probably need to resort to a different ux to completely fix these caching issues.