iPhone 15 Signal Issue

Brand new iPhone 15 and the signal/reception is atrocious.

Every UK network every forum has the same issue.

I have called apple customer care, and gone through the motions and still nothing changes! My old iPhone 13 never had any network issues!!! I don’t have a dud we are having the same issues with the other 3 15’s in the office. Apple when are you going to address this issue?