Need Some Advice People. Phone Related

People I have an iPhone 8+ i had it paired to my sena headset SMH5 it worked last year. But now i can't get the sound on it. It has like a whisper. Any one throw some light on the problem

 

I took the phone and bits to infinity today. They played around with it and it worked. Riding back home to Burnham Bucks stopped at McDonalds for a coffee. Started my journey again it stopped talking again. All i get from it now is proceed and you have arrived at your destination no turn right or left take third exit on roundabout if you get what i mean.