Windows11 (22H2), display resolution 3840x2160, win scaling 150%
Browser - categories
no duplicate check when creating Category via Category Sets tab
To reproduce:
1. run clean portable XnViewMP (Browser mode)
2. goto Categories > Category Sets tab
3. press Enter in Create field
category properties dialog will popup
4. press Enter again
5. repeat steps 3,4 few times
Categories tab will have multiple categories
however, they will "merge" into one after restart

ps. no such issue in 1.4.5