Text column field does not fill with m4a files that already contain text

Greetings. On the main page I inserted a "Text" column. I need it to check whether I have inserted the lyrics between the tags in a series of songs (synchronized or not). Strangely, for "flac" type files the field fills up; for "Alac"(m4a) it does not fill. How to make sure that it is filled also for the "alacs"? Thank you.

Have a look at the extended tag-view (ALT-t) of your problematic files whether you can find your expected lyrics and in which tagfield they are saved. This should correspo0nd to your created column.