I’m using an iPad Air2 running iOS 11 and Control version 2.9.0. I can connect to my two H9 pedals to my iPad just fine. The problem begins whenver I briefly switch applications and then return to the Control application – this is when Control loses its connection while the iPad bluetooth is still connected. The only way I’ve found to reconnect is to exit the Control app, turn off the iPad bluetooth, turn on the iPad bluetooth, and then reconnect the H9 bluetooth – which will bring up the Control app again. So, it seems that once connected to Control I can’t leave that application without having to go through the process of reconnecting again.