Bug seems to be fixed in 14.2 Beta 2!

@meaton The problem persists in 14.0.1 and 14.2 Beta. Do you have a hint for what to look in the system_logs.logarchive?

We experience the same problem in a slightly different constellation (IKEv2 profile for iOS configured by XenMobile MDM). Our IKEv2 profile is configured as "always on" for 4G and WiFi. It cannot switched on or off by the user. After the iOS 14 upgrade it is not possible to use the 4G network (VPN: Connecting...). As Qixin mentioned the workaorund that actually works is to use the WiFi connection (VPN: Connected), switch off WiFi and from that point on VPN on 4G is working as it is supposed to. The same procedure has to be repeated after rebooting. Would be great to get some information on that issue.