Directory thumbnail refresh issue

[blackxacto]

Using Big Sur 11.4, XnViewMP 98.4:

I've noticed that the refresh of thumbnails within any directory, but especially my main 2,100 image folder directory is inconsistent. Each time I make changes, or I open XnViewMP, there are duplicate thumbnails. So, I combo refresh, Rebuild Thumbnails, Update Catalogue files, but I get tired of doing this each time I open XnViewMP.

Have I reached a maximum XnViewMP image count for any directory, or does the latest XnViewMP version have bugs?

[xnview]

I've noticed that the refresh of thumbnails within any directory, but especially my main 2,100 image folder directory is inconsistent. Each time I make changes, or I open XnViewMP, there are duplicate thumbnails. So, I combo refresh, Rebuild Thumbnails, Update Catalogue files, but I get tired of doing this each time I open XnViewMP.

you have bad thumbnail for some files?

[blackxacto]

I purchased Stellar Repair for Photo-Mac, reasonable yearly subscription. It seems to have completely revitalized XnView viewing my folder of 2200+ jpgs. There are no more double images in the database from bad cache. Renaming changes are lightning fast now.

I had no idea that jpegs need repairing. Some needed "Advanced Repair" by Stellar. I thought a jpeg is just a flat image, but apparently it is a group w two main parts. I guess one part gets messed up and needs repairing. Apparently the container part is priority, and if damaged, the file is corrupted beyond repair. Luckily none of my containers were corrupt.