Hello, I got the problem yesterday night, and I just managed to correct it :
Malwarebytes was actually blocking a connection entry from steam ( so check if you have it or something like this that can block the connection of an application) . I uninstalled it , rebooted the pc then opened the game again. 10 of the 19 mods that showed up as workshop-number updated.
I did a little thing to do , I think it was not really usefull but I'll put you the link in the end in case it doesn't work.
After uninstalled Malwarebytes and seeing how it worked, I unfollowed the rest of the corrupted mods ( you can see what they are when you click in show info next to the update button in the game) you reboot your pc and then you check if they have dissapeared in the game. If yes, just follow them back and everything will work.
I hope it'll help. And here the link if it doesn't work: