OpenVPN services not restarting after PPPOE restart

[sysgi1]

Hello,
I have some trouble with my PPPOE connection, so sometimes it goes down for like 2 or 3 minutes.
The problem is after the PPPOE back up, my Netgate SG-5100 seems to loose the ability to restablish OpenVPN connection it hosts (server mode), it's like it is unreacheable.
I have to manually restart the openvpn service to let it works again.
I'm running version 21.05.1, but the same thing was also happening in version 21.05.
I don't recall any similar problem in previous versions.

Could you please help me?

Thank you

[sysgi1]

Update: it seems that when PPPOE goes down, OpenVPN service start listening on an ip alias of my WAN interface and not on the main address.
After the service restart, it correctly goes listening on the main ip address.

Any tips how to avoid this?

[sysgi1]

@sysgi1 Anyone? Is there any issue with OpenVPN in a multi-ip environment?
I think something is broken in the last version (I never had this problem prior to 21.05 upgrade)

Thank you