With the old UC surface when I used to toggle between UC Surface (Controling my RM16) and Onsong (I use for charts & midi control) and back again, UC Surface always took a few very irritating seconds to reconnect, and now with Universal Control 2.0 this seemed to have been fixed, and when I want to change my mixer setting on my Ipad air 2 I jump out of Onsong and back into UC Surface and it misleadingly appears to be instant, however it constantly now seems behind the scenes to not reconnect to the RM16. I can move the faders and everything but it does not change the mix, and if I go into mix presets it only shows local device ones. I then have to close the app completely and re launch it and wait for it to connect from scratch, and thus it's now worse than before because of the extra step of having to quit and relaunch before waiting for connection. Also the worst thing is, because it lets me actually change things as if its working, it is hard to tell if it is disconnected until I try change something and it doesn't work. Very irritating when between songs you need to make a quick subtle change in the mix, but have to reset everything.
I'm hoping you have a solution for this ASAP as it is a major issue for me causing embarrassing dead air moments at gigs while I have to work around the issue.