I am having the same issue. I have disabled “Use genre’s from Roon’s metadata database” and rescanned my library. My test track/album, both correctly tagged as “Jazz”, and ONLY “Jazz” still appear in the “Blues” genre.
This appears to be an ongoing issue. Are there any new solutions?
Topic may be the same, but the fix for the issue in the thread was issued five years ago. If you’re having a problem now, I suggest you follow Ged’s advice and raise a new Support request. Detailing your setup will help in diagnosis of your issue…