A few days ago, I was running a newer scenario from Elphaba (Donner Detour - GWD034). I had to save my progress and return to it later. Last night, I resumed the scenario, and all seemed completely normal.
This morning I realized that none of the 20 or so most recently added workshop scenarios are no longer available in my in-game menu. I've never seen something like this before. It's possible they were missing yesterday too - I didnt check. Furthermore, any workshop scenario that I've begun is still available through the standard scenarios, but not the Collection/Workshops menu.

After a futile google search on this problem, these are the things I tried:
-Clear game blueprints cache
-Unsubscribe/resubscribe to the missing items
-Delete contents of railworks/Temp folder
-Verify integrity of game files
So far, nothing has helped.
Any ideas? Is there a corrupt database somewhere?