Just a heads up, I have updated an XR which completed the update to iOS15 in under half an hour, the iPhone 11 Pro Max which I set off at the same time took over two and a half hours. I was concerned the pro max update had failed, was stuck on the Apple logo and update for a long time, but did update eventually. Definitely the longest I've had to wait for a phone update, but just be patient (I was on the verge of attempting a reset through iTunes).
