Can't save banners, endurance playlist unlock taken away from me

Hello. I was playing Unbound earlier this week and noticed my banner had been reset. I went back to my garage to change it back to the banner I had unlocked for "Complete Endurance playlists", only to find it had been locked again. If I try to pick a different banner instead and close out of the menu the game simply tells me "Save Failed" with no other error details explaining what's caused the problem.

I've verified the installation, checked file permissions, restarted my PC and the game, nothing else seems wrong. This has been going on for at least 2 days now and it's starting to irritate me a lot.

Video: https://imgur.com/a/RY5WPUi