Tried the upgrade on some shared iPads to see how compatible it would be right out of the box and found that all devices lost internet connection.
After some digging I found the "private adress" was enabled by default in the wifisettings and that was the culprit of the error. Our routers does not seem to be handling this setting well.
Did a search in JAMF to find out if it is possible to disable this to avoid manual work on upgrading our 1000+ units to 14 further ahead. I could not find any payloads for this setting.
We're on JAMF 10.21 and I'm checking to see if there might be some more input on the subject?