I have not been able to replicate the issue, could you please try the following please:

1) Clean install MM5 2268 as Portable and scan just the one album (for which you could replicated the issue previously)
2) ZIP content of whole your /Portable/ folder and copy it to a temp location
3) ZIP content of the album files and copy it to a temp location
3) Run DbgView (item 4b here: https://www.mediamonkey.com/forum/viewtopic.php?f=30&t=86643)
4) run the MM5 2268 portable version and try to replicate the issue within the album and indicate in which view you tested the mass edit
=> if you can still replicate then send me the ZIP of you Portable folder and the album files from step 2) so that I can replicate it too + debug log
e.g. upload those files to DropBox and share the link with me via private message.

Thanks!

The problem persists with lyric lookup disabled.

Looks more like it may be realted to the previously reported comment issue, as I'm seeing the same thing when I batch edit comments.

I cannot replicate, but isn't it that it auto-searches for the missing lyrics of the selected track?
Go to Options > Metadata Lookup > Background metadata lookup
and disable '[ ] Lyrics' checkbox there, does it help to resolve this issue?

Sounds like: https://www.ventismedia.com/mantis/view.php?id=15812

I've been going through removing lyrics that aren't actually lyrics. But when I grab a selection of tracks and try to clear the lyrics, it keeps doing all of them except the first track: https://screencast-o-matic.com/watch/cY6h2MK0Eu

So far, I'm only seeing this when I try to edit lyrics. I've been able to update artist, album, etc. without a problem.

I'm running MM5.0.0.2268.