I can only repeat that you try this:
Could you check, if the "hanging" also occurs if you do not open MP3tag via the Explorer context menu but open the folders/files from within MP3tag (and its functions to access the filesystem)?
On several occasions modifying ones workflow solved the problem.
And give feedback?
Also: Even only opening the folder at the same time in Windows Explorer sometimes blocks decent file access as the Explorer tries to update its thumbnails. A real nuisance.
Ah yes: could you give feedback if it worked?