Map not showing up in map selector since 0.23

An old map (Blackhills by Ouerbacker) isn't showing p in the map selector screen. I assume this is due to the fact it hasn't been updated in years. Any way to "make it" compatible again?
I already tried reinstalling it from the repo, and verified game integrity. I also tried it in safe mode, without success.
Thank you in advance for help, as it is my favorite map.

Edit: I also tried clearing the cache, without result

 

I am also having some old maps not showing up, same issue.
To have them work before, I had to create a "levels" folder within the mods folder, and add the older maps there. This seems to no longer work. They are even counted as activated maps, just not showing up in the map selector.

 

Yes, exactly the same issue. It is weird that they are recognised by the repo but aren't showing up. 0.23.2 Didn't fix it either...