Bluetooth Headset causes onscreen keyboard to be disabled
I have an iPhone 7 running iOS 10.2 (14C92) and a Sony SBH54 Bluetooth Headset.
I have noticed, recently, that when I have the headset connected, the onscreen keyboard no longer works; in fact it does not appear on screen as expected. If I disable Bluetooth on the phone or power off the headset then the keyboard comes back!
I can not recall when this problem started - whether it was an iOS update. In fact I am not even sure if it is an iOS issue or a problem on the Headset - though the most likely candidate would seem to be the phone.
With the iPhone 7 now not having the headphone socket, as you can imagine this is quite problematic!