Album Artist not showing in MP3 files

I have been using Mp3tag for years with FLACs and have not have any problems.
Now I'm using dBpoweramp Batch Converter to generate MP3s for use with iTunes, and have a question. I appreciate that this could be an issue with my use of dBpoweramp.

My initial problem when viewing the MP3s was that there was nothing showing for Album Artist, Compilation or Cover Art.

By selecting APE in Tools | Options | Tags Mpeg I can now see Compilation and the Cover Art, but not Album Artist.

For the MP3 files, File Explorer shows the correct Album Artist value in the ID-Tag pane, but the Details pane does not show any value. I guess this is why Mp3tag isn't showing anything.

Is there any way of getting Mp3tag to see the Album Artist value that is on the ID-Tag pane?

I would first of all check which data is stored in which tag version.

In Tools>Options>Tags>Mpeg

set first only APE to read, all others off
and load the files or press F5
check which data is displayed.
then set only V2 to read, all other off
and press F5
and check which data is displayed.

There is no real way to move data from one tag version to the other ...
But you could export the (visible) ALBUMARTIST to the filename (if that is stored in APE tags).
also, export the cover art to a file in the filesystem with an action of the type "Export cover to file" and a filename pattern that creates a unique filename and can be deducted from the tag data.

Then set to read and write the V2 tags, switch off read and write for APE.
Then use the converter>Filename>Tag and import the ALBUMARTIST
For cover art, use an action of the type "Import cover from file" using the previously applied export mask plus extension.

I would avoid using APE tags, as there are issues with support on most modern players. You can set dbPoweramp to write id3 tags by default, I recommend you do that with v2.3 and UTF-16 for the best compatibility.

The other thing to check is to ensure the actual tag written is “AlbumArtist” rather than “Album Artist” (no space).

I experimented having Mp3tag reading each of the tag standards one at a time.
APE displayed Compilation and Cover Art
ID3v1 displayed none of them
ID3v2 also displayed none of them, and also Artist, Album and Title were missing.

When I changed dBpoweramp to write using ID3v2 v2.3 for tag creation and Mp3tag to read only ID3v2 - all was good.
I can now see Compilation, Album Artist and Cover Art.

Thank you both for your help.