Steps to reproduce:

1. Create host, add item and trigger
2. Add tags a:a and b:b to the host
3. Add tag a:a to the trigger
4. Edit trigger
5. Open tab "Inherited and trigger tags"
6. Click remove button for tag a:a
7. Update trigger
8. Edit trigger

Result:
The "Remove" button has become disabled. After saving the trigger, the tag is not deleted.

Expected:
The "Remove" button has become disabled. Fields name and value became disabled. After saving the trigger, the tag on the trigger is removed, but still inherits from the host in tab "Inherited and trigger tags".