RT-AX58U OpenVPN client cannot connect to the OpenVPN server when it reboots at a new IP even though DNS points true

[JD-Atkinson]

Router Model Affected
Models: RT-AX58U V2

Firmware Version Affected
3004.388.8_2-gnuton1

Is this bug present in upstream Merlin releases too?
Unknown, but Merlin on other router clients don't have this problem, just the v2 RT-AX58U

Describe the bug
This router is a OpenVPN VPN client to an RT-AC88U VPN server that has no interoperability problems with other clients. It works perfectly well until the VPN server router restarts. Then the client cannot connect to the server. What changes when the server router reboots is its IP address. But hooks are in place to change the IP of the dns name to the new IP address. So the client connects to the DNS name, works fine, the server reboots and gets a new IP, the connection does not re-establish.

The client is setup for infinite retries so it isn't just failing and stopping. Other clients with straight Merlin (on RT-AC88U clients) navigate this no problem.

Unplugging and restarting the client RT-AX58U fixes the hangup and the OpenVPN client connects properly.

Right after the server reboot, the client shows the problem and wants to reconnect at the original IP:

Oct 14 03:46:18 ovpn-client5[18846]: [Culebra1608Server] Inactivity timeout (--ping-restart), restarting
Oct 14 03:46:18 ovpn-client5[18846]: SIGUSR1[soft,ping-restart] received, process restarting
Oct 14 03:46:18 ovpn-client5[18846]: Restart pause, 1 second(s)
Oct 14 03:46:19 ovpn-client5[18846]: NOTE: the current --script-security setting may allow this configuration to call user-defined scripts
Oct 14 03:46:19 ovpn-client5[18846]: TCP/UDP: Preserving recently used remote address: [AF_INET]174.24.83.20:1194
Oct 14 03:46:19 ovpn-client5[18846]: Socket Buffers: R=[524288->524288] S=[524288->524288]
Oct 14 03:46:19 ovpn-client5[18846]: UDPv4 link local: (not bound)
Oct 14 03:46:19 ovpn-client5[18846]: UDPv4 link remote: [AF_INET]174.24.83.20:1194

After a couple of minutes, the DNS is updated, and the client is trying to connect to the new IP:

Oct 14 03:55:40 ovpn-client5[18846]: [UNDEF] Inactivity timeout (--ping-restart), restarting
Oct 14 03:55:40 ovpn-client5[18846]: SIGUSR1[soft,ping-restart] received, process restarting
Oct 14 03:55:40 ovpn-client5[18846]: Restart pause, 16 second(s)
Oct 14 03:55:56 ovpn-client5[18846]: NOTE: the current --script-security setting may allow this configuration to call user-defined scripts
Oct 14 03:55:56 ovpn-client5[18846]: TCP/UDP: Preserving recently used remote address: [AF_INET]174.24.88.72:1194
Oct 14 03:55:56 ovpn-client5[18846]: Socket Buffers: R=[524288->524288] S=[524288->524288]
Oct 14 03:55:56 ovpn-client5[18846]: UDPv4 link local: (not bound)
Oct 14 03:55:56 ovpn-client5[18846]: UDPv4 link remote: [AF_INET]174.24.88.72:1194