FYI: it’s not an issue here but it doesn’t hurt to provide your used CMK site and agent version - but may help being most helpful in our replies… 
After defining tag groups you can configure these in two locations:
- folder properties, in order to get the settings inherited by the folder’s contents and
- host properties, to set them explicitly and break inheritance for this specific tag
Hope this helps!
BR,
Marsellus W.