Why is NEPacketTunnelProvider receiving stopTunnelWithReason NEProviderStopReasonInternalError

We're seeing some new and odd behavior where our NEPacketTunnelProvider instance is receiving a stopTunnelWithReason:completionHandler: call with reason NEProviderStopReasonInternalError.

Can anyone shed some light into how to diagnose this situation?

Here are some basic details:

• Our PacketTunnel has been in use for years and we only started seeing this issue recently.

• We're able to reproduce this behavior with some light browsing.

• The documentation provides no insight on why/when this might occur. Can anyone shed some light into how to diagnose this situation?

Things we’ve tried so far:

1. We grabbed a sysdiagnose and looked through the logs:

   a. Right before the stopTunnel, we see log items referring to a "nesessionmanager" (PID 2038) getting killed. Presumably, this is due to hitting a highwater threshold. (See sysdiagnose items listing below)

   b. Thinking these were due to memory pressure, we added logging of available/used memory.

   c. We confirmed that the PacketTunnel was only using 11,808.73 KB.

   d. Since, there is plenty of memory available the PacketTunnel was not killed for using too much memeory.

2. We wondered if this could be due to our UI's usage of objects like: NETunnelProviderManager and NETunnelProviderSession

   a. We ran an experiment where we swiped closed the UI to ensure these manager/session objects are not used.

   b. Without the UI, we still saw the random stopTunnel with NEProviderStopReasonInternalError.

3. We wondered if our routes were the problem, but they seem correct.

   a. See the NEPacketTunnelNetworkSettings listing below

LISTING: From the system_logs.logarchive, the nesessionmanager log items:

2025-01-23 15:07:59.176146 -0800		0x278	memorystatus	com.apple.xnu	memorystatus: killing process 2038 [nesessionmanager] in high band ? (140) - memorystatus_available_pages: 18932	default	kernel
 
 
2025-01-23 15:07:59.179641 -0800		0x278	memorystatus	com.apple.xnu	memorystatus: killing_highwater_process pid 2038 [nesessionmanager] (highwater 140) 7056KB - memorystatus_available_pages: 19161 compressor_size:69593	default	kernel
 
 
2025-01-23 15:07:59.179888 -0800		0x278	memorystatus	com.apple.xnu	memorystatus: failed to kill a process and no memory was reclaimed	default	kernel
 
 
2025-01-23 15:07:59.185695 -0800	1	0x45e0c		user/501/com.apple.nesessionmanager [2038]	exited with exit reason (namespace: 1 code: 0x2) - JETSAM_REASON_MEMORY_HIGHWATER, ran for 266329ms	default	launchd
 
 
2025-01-23 15:07:59.231188 -0800	31	0x45bf2		com.apple.networkextension	nesessionmanager(2038) exited	default	UserEventAgent
 
 
2025-01-23 15:07:59.253371 -0800	31	0x45bf2		com.apple.networkextension	nesessionmanager exited with active sessions, re-launching nesessionmanager to clear agent status	default	UserEventAgent

LISTING: From the system_logs.logarchive, the stopTunnel from PID 2046

2025-01-23 15:07:59.201581 -0800	SamplePacketTunnel	[Extension com.REDACTED.PacketTunnel]: Calling stopTunnelWithReason because: None
2025-01-23 15:08:20.783112 -0800	SamplePacketTunnel	2025-01-23 15:08:20,786 2046 ERROR REDACTED (285805) - Exiting after waiting for stopTunnelWithReason

LISTING: routes from NEPacketTunnelNetworkSettings

 {
    tunnelRemoteAddress = fd12:3456:789a:1::1
    DNSSettings = {
        protocol = cleartext
        server = (
            2606:4700:4700::1234,
            2606:4700:4700::2345,
        )
        matchDomains = (
            ,
        )
        matchDomainsNoSearch = NO
    }
    IPv6Settings = {
        configMethod = manual
        addresses = (
            fd12:3456:789a:1::1,
        )
        networkPrefixLengths = (
            64,
        )
        includedRoutes = (
            {
                destinationAddress = 2606:4700:4700::2345
                destinationNetworkPrefixLength = 128
            },
            {
                destinationAddress = 2606:4700:4700::1234
                destinationNetworkPrefixLength = 128
            },
        )
        excludedRoutes = (
            {
                destinationAddress = REDACTED
                destinationNetworkPrefixLength = 128
            },
            {
                destinationAddress = REDACTED
                destinationNetworkPrefixLength = 128
            },
        )
    }
    MTU = 3072
}

Thanks for taking a look, any help or suggestions would be greatly appreciated