Dynamic state reset

[Wired Life]

Hello guys,
I'm facing an issue that I can't seem to solve correctly and I'd love to get a tip of best practices:

I've 2 wans, one of them is a PPPoe and has it's target gateway changing from time to times. As I've a SIP PBX in the background, I've set the "Dynamic state reset" flat on the advance param. Unfortunatelly, this flag does not seem to be compatiple with the OpenVPN client that I use, as once the VPN client receives via DHCP an new ip, the states are reset and the connection is dropped.

Can I somehow enable the "Dynamic state reset" flag only for one interface? Or is there anoter way to achieve this ?
Thanks a lot in advance and best regards,