It would be possible to try to auto connect from the H9 to the last paired device and we experimented with this as a feature for a while, but this is a much less attractive option that having the app auto connect to the device. The problem with this is that sometimes an H9 would latch on to one device and you couldn’t get it to let go of that device.
If I’m understanding correctly, this is the same behavior as my Bose SoundLink Mini speaker. You turn it on and it takes about one second for it to pair with the device it was last paired with. If I need to pair it with a different device, I need to un-pair it from that device (I usually just turn off bluetooth) and then pair it to the device I want to use it with.
I understand that this may cause some confusion, but from where I stand it would be so much better to have this as an option. 99% of the time, I’m connecting to the iPad in my studio, and I feel strongly that the need to connect manually is the number one weakness in the H9 experience. I have two H9s – press connect, wait a few seconds, press “Ignore” when prompted to let the H9 app to connect, press connect for the second H9, wait a few seconds, then press “Allow” when prompted by the app. It’s a clunker.