This newest mp3tagv328-x64-setup release is significantly slower then the previous mp3tagv327a-x64-setup release.
Easy enough to see. Scroll through tracks with the RETURN key; there is now a significant lag between key presses and updates to the UI.
I'm going to remove the mp3tagv328 and return to the previous mp3tagv327, which does not slow me down.
TBH: I do not see any delay when scrolling the file list neither with the cursor keys (which forces no update of a file), the return key (which in fact forces an update to the file and perhaps you have switched on the library function now which you didn't before) nor with the mouse wheel ...
So it looks like something local to me
Mmm . . . Maybe Windows was performing another update in the background. God knows that slows my computer to a crawl.