I have the SR11 as well, Ethernet connected. What usually happens is that if the Fiio is turned on before you launch Roon Remote it won’t show up. In that case I just turn Fiio off and back on and it shows up in Roon as it was set up at first.
We haven’t heard back from you since your first post.
A few experienced users have provided some device-specific suggestions in the posts above. If you’ve tried those steps and still have trouble with device discovery for this streamer, then please give us a ping here.
Otherwise, we’ll assume this issue was resolved in the interim and allow the thread to auto-close after a few days without response.