Workshop assets not loading

[Newt]

So whenever I try to play a custom (workshop) game which requires me to download custom assets the game just gets stuck in the x/y (zz%) "state". I get no obvious error messages or anything, it just stops downloading. Sometimes it downloads a couple of assets (like ~5%), sometimes it just stops at 0.
Already tried reinstalling, deleting files in the "Saves" folder and simply resubscribing to workshop mods.
It happens both in public lobbies with mods I haven't subscribed to and private lobbies where I subscribed to the mods.

am on windows 10 if that helps.

[SaltyO]

1. test with firewall/av/defender turned off. if it works, that's the problem.
2. disable mod caching/mod threading and restart steam. try a few mods again to see if this fixes things.