Beats by Dr. Dre Powerbeats Pro Ear-Hook Wireless Headphones

Good morning all,

I've had a pair of the Powerbeats wireless headphones for about a year, which until recently have worked great with my iPhone 11. However, out of the blue, the left hand channel has stopped working, I've tried swapping them over and still the left hand doesn't work, so I know it's phone and not the headphones. I have tried disconnecting and re-connecting and nothing seems to work!

Any ideas on what I might be able to do, to restore the connection?

Kind Regards,

Simon