There were no changes within iOS 11 GM and the official release yesterday. The issue is still happening on tenants within O365 that have HTTP/2 turned on. I had the pleasure of working with Apple and MS over the last 2 weeks sending them logs and other information. You also have to understand, Apple does not use O365 internally or externally so they wouldn't have caught this issue. They have a lot of bug reports that people send in. Most of those users don't even try to troubleshoot by turning it off and back on again. Beta software is supposed to be run on non-production devices. So part of the troubleshooting expecting by Apple is for a restore to be done, eventually. Most people that run the public beta, its on their full time device so many of the bug reports weren't complete and others just didn't work with Apple on the issue. Plus, with everyone saying they sent a bug report, they can't get to everyone who reports a bug.