iOS 16 stuck checking for mail

We are having a problem after updating to iOS 16 with the mail app getting stuck at checking for mail. I have not been able to identify a sequence of events to cause it besides the mail app being open or open in the background. It happens on both wifi and cell data. It will happen throughout the day without getting up or moving around. We have had reports of this since 16 came out and still happening in 16.1, happens on both the new iPhone 14 and older phones. We have about 10 people reporting this problem at this time.

We have restarted the phones, Turned mail off then back on, removed and readded the mail account, tested both wifi and cell data, tried different fetch schedule settings automatic and 15 minutes even thought the accounts are set to push.

The one workaround I have found is that if the mail app is closed new mail notifications always work on the home or lock screens. but after reading the messages if you don't close the mail app again it will eventually(normally within an hour) get stuck checking for mail and no new messages or notifications will come in.