Wireguard via DHCP WANs in a Failover Scenario

[ricksense]

Hi everyone,
I created two LABs in virtual environments, each running OPNsense as a firewall/router of their own LANs.
I also set a dual WAN failover on their WAN ports (one port with static IP, and a dhcp client on the other).
I then set a site-to-site Wireguard tunnel between the two OPNsense machines to make their LANs reach each other. Everything works great so far.

However, I noticed that the tunnel works as long as a WAN with static IP is UP on at least one side of the two LABs; in other words, if the two "static IP WANs" fail on both sides, the Wireguard tunnel stops working even though the two DHCP WANs are regularly up and the clients on both sides can go out to the Internet.
Is this expected and considered normal behaviour in a real-world scenario too?
Thanks