VPN issues from flapping secondary connection?

  • So I have a customer with dual WAN. No load balancing, just failover (the primary connection has much more bandwidth).

    There is a site to site IPSec VPN to one of their vendors. That IPSec connection does not use a Gateway Group, it only makes the connection on the primary.

    All day yesterday, they're saying they're getting disconnected from the other side of that VPN. The VPN is not showing that it's disconnected, and there haven't been any issues on the primary WAN.

    What I am seeing, however, is the backup, secondary WAN has been constantly flapping. Could this be flushing some table and causing issues on the VPN on the primary?

    Version is 2.4.4-RELEASE