If you have a virtual machine running locally, that virtual machine should be accessible via whatever ip address is assigned to it's virtual port.
I'd look there first.
If you can't look there because when the load balancer is running you can't access your X server you're probably going to need to access the thing from another machine running on your network, or more accurately from another machine running on the subnet that your virtual machines IP port is assigned to.
If you notice in the example from the page you referenced, the web admin UI is being accessed via direct IP
(though it's partially obscured) and not https://vip_of_zenlb:444
Do me a favor and if you read this and try the suggestion, whether it works of not, let us know what the result is. I'm wondering how you dig into this beast, just like you. If you don't share the answer, I don't come out of this any smarter.