IPSec VPN stuck on connecting state when switching off mobile network

I have an MDM-managed iPhone 6(iOS 12.5.1) with IPSec(IKEv2) VPN enabled. VPN connects onDemandRules were set in the profiles.

When the VPN is connected and running(both mobile and WIFI network are switched on) I switched off the mobile network, then the VPN stuck on Connecting... state. And I can always reproduce the same issue with the same operations.

I checked the log on the Console and the following messages seems suspicous:

Code Block
default 11:30:27.808837+0800 nesessionmanager NESMIKEv2VPNSession[blob VPN:C350FBBE-06BE-41AD-8558-277DCECC5C4A]: got On Demand start message from pid 98
default 11:30:27.809324+0800 nesessionmanager NESMIKEv2VPNSession[blob VPN:C350FBBE-06BE-41AD-8558-277DCECC5C4A]: Received a start command from apsd[98]
default 11:30:27.809504+0800 nesessionmanager NESMIKEv2VPNSession[blob VPN:C350FBBE-06BE-41AD-8558-277DCECC5C4A]: Skip a start command from apsd[98]: session in state reasserting
info 11:30:27.809952+0800 nesessionmanager Handling a com.apple.networkextension.file-descriptor-maintainer event
debug 11:30:27.810134+0800 nesessionmanager Ignoring additional event in owner mode


To my understanding, it seems that when I toggled off the mobile network the VPN went into a reasserting state, and at that moment an onDemandRule was matched but was skipped due to the reasserting state.

When I tried the same operations on an iPhone 12 mini(14.2) there is no such issue.

Is it a known issue on iOS 12?
IPSec VPN stuck on connecting state when switching off mobile network
 
 
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