Listing tag-related files

I have a problem with the basic listing of files with a certain tag.
It has worked fine so far, but now don’t seem to work.
The only change I remember to have done is some moving with the file manager.
Is it possible that I messed up the tags by doing some wrong operations?
For example, I read that I can safely move the folders with the file manger, but what about files? Should I move them only with TagSpaces in order to maintain the tags?

Anyway, at the moment it doesn’t list folders with a certain tag as well anymore (but it had worked fine so far).

I am currently on Ubuntu 20.4. I have downloaded both TagSpaces app-image and the executable x64 that work well for the rest.

Moving folders is safe, because all the meta information like tags and description are in this folder. But if you use the sidecar tagging method and move or rename files outside of TagSpaces, you will loose the connection between the sidecar files and the renamed files…

I think I had even read it somewhere, but I forgot.
So this is currently a main point I have to keep in mind, one can use the file manager for moving folders but has to use TagSpaces for moving files.
Thank you for the explanation!