can't make XSPF open in VLC - opens in firefox first

[URDRWHO]

I have VLC installed and have some XSPF files that contain radio stations for VLC to stream. When I click on the XSPF the desktop goes to Firefox first and then opens in VLC.

I have used the method to open by using choose open with/ choose other / choose VLC / tic the box to remember file association for this file type. You get a pop-up saying that updating system config and the file opens in VLC. It won't remember the association and next time I click on a XSPF file it opens in firefox and then VLC.

I've gone to system settings / file associations and removed Firefox from the hierarchy of programs that will open XSPF files. It still opens in Firefox first.

I know that in windows that once you choose to always use a certain application to open it a file, that is what it does. Not sure why kubuntu isn't doing the same thing?