Cannot upload and/or sync certain files

Hey, i have been using nextcloud for quite a while an now noticed, that nextcloud client on windows is not syncing certain file types correctly, like .db files (or atleast not showing that correctly in windows explorer)

For example i have a bunch of thumbs.db files on my nextcloud instance and i have that integrated in nextcloud explorer and all files are showing correctly with either blue or green cloud symbol, but for some reason all .db files are showing permanetly with the loading symbol, no matter what i do.

Not sure if this happens for other file types aswell, i just only checked for .db files