#30 Corrupted thumbnails in the Library

[Finder X]

In the Library, after add new books, or zip files, the thumbnails become corrupted.
I attach a screenshot so you can see what is showing.

I have 1500+ zip files, maybe is something about that, but in early versions of mcomix (v2.x) this problems is not appears.

I'm using the Flatpak version, because the linux mint maintainers had the version v1.x.

[Finder X]

I tried change the Thumbnails size and sometimes make the thumbnail correctly but when go back to my desired size, some other random books cover thumbnailes are corrupted.

Is so random, even when before covers were fine, and then are corrupted when close and open the library again. Is not an only zip files, is every zip file.