an update to this.
We deployed the following workaround and it seems to work for us:
We deleted the teams app from the iOS device, as the app pre-existed on the device before the per-app Vpn deployment, and the resend it from AW1 and now we can successfully accept calls and join meetings.
What we also had to deal with before, was some firewall rules too, but this depends on the current config of each case.
I hope it helps!
I did some more testing with iOS 14 beta 1 and Teams 2.0.15. It was not working for me, but at some point Teams crashed during my testing. Strangely, after this crash, Teams starting working properly using per-app VPN over Tunnel. I continued to test it quite a number of times, and it worked consistently.
I left for vacation and came back this week. I noticed that iOS 14 beta 2 and Teams 2.0.17 came out. I updated my device to both. After doing this, joining a meeting in Teams would not work again over per-app VPN. After multiple attempts at testing, Teams crashed again and actually caused my iPhone to power cycle. When the phone came back on, Teams started working properly again over per-app VPN! I continued testing it, and it worked for a while. However, I decided to change Teams to the Dark Theme, and after Teams restarted, joining a meeting stopped working again.
So while it seems that iOS 14 has addressed the problem in some capacity, it is extremely inconsistent.
I have a puzzling update. iOS 14 beta 3 came out, and the behavior has continued to remain inconsistent. Sometimes joining a meeting in Teams works fine over the per-app VPN connection; other times it does not. I worked with the engineer to submit more logs, but time is running out to get this fixed before iOS 14 goes public.
Having said that, one of my colleagues informed me that Teams started working properly for her on her iOS 13.5.1 iPhone. I've now tested a number of my test devices running iOS 13.5.1, and they all seem to be working properly and consistently. We have not made any changes in our AirWatch/Tunnel environment, and Apple stated that no changes to per-app VPN were made in iOS 13.5.1 or 13.6. I even tested this on one of my devices running iOS 13.4.1, and it works there too. The only thing that has changed recently are newer versions of the Teams app. However, Microsoft stated that this wasn't a problem with Teams, so I'm not sure why newer versions of Teams would have potentially fixed this problem.
Has it started working for anyone else?