Help with m4a "Description" Tag

[ByMinotti]

@Minotz

I have attached two screenshots while playing the file in foobar2000. When I click on Metadata Properties it shows the Description field. If I open the file in Mp3tag and add something in the Subtitle field and then play the file in foobar2000 it adds the
Subtitle field under Description. I am still unable to see what is typed in the Description field when I open it in Mp3tag. Thanks for your help.

I just opened up "Customize Columns" in Mp3tag and tried creating a description column one more time. I put the value and field both %description% and that worked. It is now showing what is typed in the Description field in Mp3tag. I am not sure why this didn't work originally but thanks everyone for all of your help!!