I did that and at first I thought it had worked but I was wrong. My final contact with Apple Support, they wanted me to post it in to have a technician repair it.
I've now got an iPhone 11 and I'm very pleased with it. The old phone is on Gumtree!
p.s. - I realise that I'm very much in the minority but I'm by no means the only person who has had the problem.
Edited by longedge (Sat 12-Dec-20 12:59:25)