Composer Field Not Uploading Correctly

I have now refreshed the song list in both mp3tag and MusicBee, reran everything.

No change, still cannot see the Conductor entries in MusicBee but can see them in mp3tag.

Then add the Conductor manually in MusicBee and load that track in Mp3tag.
Show us a screenshot from View -> Extended Tags.

I updated the file Mobile by Ray Burns with the Conductor Eric Jupp [New Entry] in MusicBee:

Here is the result in mp3tag:

I also updated the file Ronnie Hilton - A Blossom Fell with the Conductor Frank Cordell [New Entry] in mp3tag:

Here is the result in MusicBee:

As you can see if I update in MusicBee, it updates and shows in mp3tag with no issue.

If I update in mp3tag it does not show in MusicBee.

What did you enter in MusicBee as Conductor:
Frank Cordell [New Entry]
or
Frank Cordell

I entered neither in MusicBee, in that test I entered Frank Cordell [New Entry] in mp3tag. Saved and then refreshed the data in MusicBee and took a screenshot to show that it's blank in MusicBee.

Please follow my instructions or I can't help you further.

The first post with the screen shots is exactly what you asked me to do! (The one with Ray Burns)

I followed your instruction exactly.

The second was the reverse as I suspected you would ask me to do the opposite as well.

Which Mp3tag screenshot shows which Conductor entered in MusicBee?

There are 2 posts one after the other. The first is for the file Ray Burns - Mobile. You can see that on both screenshots in the title and artist fields. This post is the entry made in MusicBee and the result. (POST 43)

The second post is for Ronnie Hilton - A Blossom Fell, again visible in the artist and title fields. This post is the entry made in mp3tag and the result. (POST 44)

Each screenshot from mp3tag is paired correctly with the MusicBee sceenshot.

Sorry, please follow only the steps I'm asking for.

  1. Delete CONDUCTOR and CONDUCTORS in Mp3tag in your "Ray Burns - Mobile (Single).mp3"
  2. Load this track in MusicBee - There should be NO Conductor visible. Confirm that.
  3. Write "MusicBee Conductor" in the Conductor field in MusicBee, save this change.
  4. Load this changed "Ray Burns - Mobile (Single).mp3" track again into Mp3tag and take a screenshot from Extended Tags (where is "MusicBee Conductor" filled in)?
  1. Deleted successfully.
  2. Confirm there is no Conductor visible.
  3. Entered successfully.
  4. Reloaded track, screenshot below:

OK, so we know for sure that MusicBee is filling the field CONDUCTOR.

Now

  1. Again in Mp3tag, doubleclick the CONDUCTOR field in "Ray Burns - Mobile (Single).mp3" and overwrite the content with "Mp3tag Conductor". Save the change.

  2. Load this "Ray Burns - Mobile (Single).mp3" in MusicBee and check what MusicBee shows as Conductor? Still "MusicBee Conductor"? Or "Mp3tag Conductor"? Or anything else?

(This is literally what I was doing with the previous two posts you didn't understand but OK)

  1. Updated to Mp3tag Conductor:
  2. Screenshot from MusicBee shows "MusicBee Conductor":

And I refreshed the data multiple times throughout the process.

MusicBee is still showing "MusicBee Conductor" instead of the expected "Mp3tag Conductor".

I assume, you have followed the hint from @MotleyG in answer #8:

However if you make any changes outside of either player [what we did in Mp3tag] you have to force a library re-scan to capture the changes. If you have the mp3tag option set to not update the system "Modification Date" then these changes will not be captured.

Please check your File -> Options -> General setting for "Preserve file modification time when saving tags":

Then ensure that MusicBee re-scans your modified "Ray Burns - Mobile (Single).mp3" into its own library.

You can enforce to re-read this file, if you rename it to something like
Ray Burns - Mobile (Single) changed with Mp3tag.mp3

What is MusicBee showing in Conductor for this "new" track in its library?

There are several ways to force a rescan in Musicbee.
To rescan on file-basis:
Mark the files you want to rescan.
Right Click -> Send to -> File rescan

Do you know if MusicBee only rescan files that have a newer file modification/last accessed date since the last MusicBee scan?

It's been a while since I've tried Musicbee.
The file-based function I described corresponds to Mp3tag's CTRL-t, so it forces a rescan.
You can also use "Send-to -> Rescan" on selected artists, etc.
Otherwise, there are some settings under Preferences -> Library ->, e.g., to perform a rescan when restarting the program or functions for monitored folders. Their functionality depends on the modification date.

It's not clear if you are saying the Preserve file modification should be ticked or not:


Mine is not.

Now it's showing:

So in theory there needs to be some kind of refresh. (Bearing in mind I have removed all the tracks from MusicBee and readded them multiple times.)

So to get all 266 files to show updated conductor I would need to mass rename them all and ername them back? That seems a wild solution.

Plus the oddest thing is that csv upload was to update the conductor and the genre fields. It uploaded and showed the genres fields perfectly but not the conductor field?