While setting up the forums I decided to create a "Applications" Thread Tag. To move our apps I deleted the "General" tag they were associated with:

"New Thread Tag for the current one
Move all threads currently associated with General to:"

Now the "Number of Threads" are still there but I cannot see the apps anywhere, even if I filter "All" ty in advance

Fixed. My apologies for that. I'm going to look into this issue further.