Remove WM/MediaClassPrimaryID tag

[solver]

My MP4 files contain tag which I would like to remove.

In MediaInfo program I see:

<extra>
<Xtra>WM/MediaClassPrimaryID</Xtra>
</extra>

In GodFather program I have tried to uncheck 'Try to preserve All ID3v2 frames' and also tried "Remove Tags". All tags were removed except tag mentioned above.

Is there any way to do this?

[jtclipper]

I am not sure if those can be deleted as of now, send one of these files to have a look