Loss of wireless charging since IOS 17.5.1 update on IPhone 11

Since the latest update my phone will no longer charge wirelessly. It does initially when put on the pad but stops after a few seconds and the pad flashes. I have tried other wireless chargers and an older IPhone which I have charges fine so its not the chargers. If I plug the phone in direct it will charge but takes many hours. My phone is less than two years old as I have an upgrade due in just over a month. Is it the phone or the upgrade as it was charging ok beforehand.