iPhone 15 Pro poor data reception

Just upgraded from an 11pro and now I can’t get a decent data reception in my house any more and also on familiar routes outside where the reception was fine on my 11. I can see from the forums that this is a widespread problem of the 15 and I’ve tried many ways to fix it but no luck. Operating system and carrier updates are current. Have swapped to 4g but no luck. I’m guessing this might be a hardware design fail or Apple would have fixed it with a software update. Anyone any success in fixing the issue? Thanks