Can you explain a little more about what you did here Peter?
If you organized your genres to someplace new in the hierarchy, it will appear under the parent genre you choose – for instance, if you chose to make “Classic Rock” a sub-genre of Rock/Pop, you’ll need to be click Rock/Pop to see it.
Alternatively, any genres you map will no longer be displayed in Roon – they’ll be replaced by whatever you’ve mapped them to. For more information about why you would want to use mapping, take a look at this post.