you dragged the XML into Rekord Buddy as a user location collection (see the line in the sidebar that says “user location”). This means you didn’t import the XML fil, you are just editing that file itself which is probably not the one rekordbox is looking at.
Remove that collection in Rekord Buddy (press delete on the line that has your user location collection) and then drag that XML file onto the rekordbox collection itself in Rekord Buddy. Not are the bottom of the sidebar but on top of the line that says ‘rekordbox’ (the first one).
That way you are now editing the file that rekordbox uses in its XML bridge.
Second you have two rekordbox collections. That’s a bug. I will contact you via DM to try and look into this with a special build.