Run into a small snag (due to miss typing the code)
For a multiple Genre you use the format Genre//genre2//genre3 and it works great however, for late night keyboarding, I used the \ instead
I tried to run a replace action
Field : Genre
Original: \
Replace with //
but that doesn't work so more scripting is probably needed. The Genre I have are different for a lot of my files so the only thing is a replace action script that replaces \ with // or another scripting function.
It could still be that you have a multi-value field for Genre right now.
Check this in the extended tags dialogue. If you see more than one GENRE field, it's multi-value.
To handle these fields, it would be easiest to merge them.
There is an action for that: Merge Duplicate Fields – Mp3tag Documentation
If you enter // as separator, you should get the preferred format straight away.