What does it mean that there are two GROUPING tags and two CONTENTGROUP tags? Three of the four have the same value, but the one that shows up in Virtual DJ and Serato is the only one not set by kid3-cli. I am setting GROUPING, CONTENTGROUP and GRP1 to try to make sure I don't miss anything. However, nothing I have done changes the one tag I am trying to change. Any ideas about how to change the one tag that has the text "CHANGE Test Grouping (VDJ)?"
Only few players can deal with multi-value fields.
To handle multi-value fields, there are some actions to merge, remove or split fields and duplicates.
You would have to find out what your player expects.
See the documentation about the actions:
Please open this song in an editor like Notepad++. This would show you what tag name is really written in front of CONTENTGROUP and the content "CHANGE Test Grouping (VDJ)".
The official ID3 tag name for CONTENTGROUP is TIT1.
Maybe you get another name for it as TXXX:contentgroup or anything else?
As you show you have 2 fields named GROUPING with the same value and as you set GROUPING and GRP1 in kid3 it is not avoidable that you get a multivalue-field GRP1, at least when you later use Mp3Tag. What you see in the extended tag-view as GROUPING is probable both GRP1.
