Thanks Jonathan,
There are no firmware updates available as running on the latest software for the streamer. It is the constant updates from apple that have caused the issue, although I am told that the application has not changed on the iPhone.
All of your other suggestions I have done, I have only an streamer connected via bluetooth and have disconnected, repaired on several occasions over the last week. The iPhone at least stays connected to the streamer, but I miss calls as the phone doesn't tell the streamer that I am being called, and the then mid way through a conversation it either disconnects or the person the other end can hear me but I can't hear them.
It is all very disconcerting and used to work perfectly, and as a deaf man I rely on this as my method of communication.