Been using this with Songbook+ for a year now and in the last few months it's started to randomly disconnect from the app running on an iPad Air. The iPad OS has been through lots of updates (IOS 11, 12 and now 13) but that hasn't seemingly affected this issue.
Sometimes it will stay connected for an hour, other times it disconnects between songs. I'm going to try the m1 controller as it's even smaller but just wondered if anyone else had experienced this with the Yamaha BT adapter.