Issue with FortiClient VPN

We are trying to set up a Balance 2 for some redundancy on the network for a home office.

WAN1 - Comcast
WAN2 - Verizon 5G

These both go into a PepLink Balance 2.

For most things, the system works as designed. IT defaults to WAN 1 and switches to WAN 2 if WAN 1 is disabled.

However, we have one computer that needs to run FortiClient to sign on to a VPN.
There is no extra hardware for signing on to this VPN. You sign on to this VPN with software on the computer.
The FortiClient did not work with the Peplink on either WAN1 or WAN2.

I followed the steps on this page.

It looks like what we needed to do was set up a Dial-up IPSec VPN

But now it looks like I need to find out what ports to turn on.
Then I followed the steps on this page.

Solved: What ports should be open to let FortiClient make ... - Fortinet Community.

As this page explains, I enabled ports 443 an 10443.

At this point, the FortiClient VPN works when on WAN 1, but it does not work on WAN2.

The FortiClient does work on WAN 2 , but it does not work if it goes through the PepLink

Are there other ports that should be enabled with FortiClient?

Is there anything else to try?