Map background isn't shown in song select (sometimes)

[Morilli]

Sometimes when random selecting maps, the background shown isn't of the map, but a default christmas-themed one that should normally only appear in main menu.
This quickly gets fixed by either selecting a different map or returning to main menu.

I haven't found a consistent way of reproducing this yet, but it seems to be connecting with playing a map (also possibly finishing it and getting a new top 1 score on it) beforehand. Here's a video showing this issue: https://streamable.com/lj7q7
I think this is a rather recent issue, as I don't think I've ever had that happen before this christmas season.

[Joehuu]

Encountered this bug again, and forgot to mention here that it won't be fixed, see #1035 (comment).