EDIT TO ADD: I’ve spent an hour with a senior support adviser at Apple via remote screen share who ran a full diagnostic report (clear) on my phone, checked and adjusted any possibly relevant settings and is confident that my device is not the problem. They recommended this be escalated to the senior engineering team at Trade Me and suspect it could be a bug in the latest update affecting some user accounts or devices or regions etc I have requested the escalation via email to the Trade Me Customer Support team member I already had contact with.  I was automatically logged out (presumably...