MWAN3 rule destination hostname instead of IP?

I have a site I visit occasionally that doesn't seem to like load balancing. I keep getting asked to log on repeatedl.

Testing a different load balance firmware I was able to fix the issue by using the hostname in a rule to only use one ISP when visiting.

Mwan3 seems to only allow IP addresses, not names, and the IP address I've found both online and using nslookup, while identical, are not the site in question. Using that address doesn't work.

Any suggestions? Can a hostname be used for destination instead?

The only working answer I've found is disabling one ISP while visiting and that's not the best answer.