got an answer in the dev-forum of ppsspp: this issues is caused by new saving-routines, also the paths have changed/shortend (from /roms/psp/psp/system/ -> /roms/psp/), so you will find saves on the memorystick there since 31.01.2022.
The issue is well known and should be fixed with the next update in a couple of days.
FYI, even if i seem to be the only one here using / updating the lr-ppsspp-core :D