@superrune I’m curious to know whether you can still connect & pair the the Ultramarc BlueHID device with Retropie ( if you’re still using either of course).
I’m using a fresh install of Retropie 4.7.1 and I’m having the same issue as you had in 2018 ie: “It connects through Bluetooth without any problems, but it seems like the Raspberry does not understand what I'm connecting”.
It appears in the list of available BT devices in the Retropie Bluetooth setup but it will not pair.
It will connect and work on my PC so it would appear the hardware is ok
I’d appreciate any thoughts or advice