back button not working on iphone message app

Thanks for that Toot Uncommon!

The option to change text size also explains something else.

My phone is a hand-me-down from my housemate. He never had a problem with the back arrow while he had it. It was only when the phone was set up for me that the back arrow stopped working. I'm guessing some settings must have been changed during setup or something.

Thanks again, and now I am going to try to work out why my original searches didn't find that post. I spent a full day trying to find a solution on the internet and didn't find the post you linked - so obviously I need to look at my search technique.