I got these tracks from someone else. There are notes in the Comment field that I'd like to erase but can't. Erasing them, and clicking Save and close has them returning when using the Edit Track Details option again.

They can be changed or reduced to one character but can't be erased completely. This happens on several different Linux distros. I'm the owner of the files and have read/write permissions.

what type of tracks are those? MP3 shouldn't show this behavior, nor should ogg or FLAC. Have you tried to edit it with a tag editor like kid3? I doubt this is an actual Amarok problem, I can modify all the comments without problems here, on any file type.

Have seen it on both .flac and .mp3 files obtained from other sources. I'll try your suggestion of using kid3 to edit the tags.