DNS VPN Link Selection Not Working

[B_P]

A public IP managed gateway is refusing to connect to the other gateways in a Mesh VPN (site-to-site) by their public IPs. Instead, it tries to connect to their internal (management) IPs. What's odd, it will do some initial connections via the public IP, then switch to the internal IP as evident in the logs with 'tunnel test' going to the internal IP. I'll also see the VPN show up briefly under the 'vpn tu' utility with the internal IPs. The internal gateways connect to each other just fine.

Gateway 'GW-D' is managed via its public IP. The other three gateways 'GW-A', 'GW-B' & 'GW-C' are all managed via their internal IPs.

I'm following the documentation here for DNS Resolving Link Selection. I have the gateway and FQDN of the gateways added to the Hosts at "Gaia Web > Network Management > Hosts and DNS > Hosts". I can ping the gateways via FQDN from the other gateways just fine. But, log continues to show GW-D trying to connect to GW-A via its internal management IP instead of the public IP as defined by Link Selection and the FQDN. I've tried both "Full hostname" and "Gateway's name and domain name" (with domain set in Global Properties) but neither work. What am I missing?

Not having any luck with VPN-Tunnel interfaces either.

Edit: diagram