Subsequent tunnels all reference the domain of the first one

I have multiple websites on my dashboard. The first time I created a tunnel it was for, say mydomain1. Now when I create a tunnel and set application controls for a new site mydomain2, I’m seeing reference to mydomain1 in the URL string. It appears the tunnel setup for a new domain references the first domain.

It may not be a big issue, however mydomain1 expires shortly and I don’t want to have to renew it.

How do I prevent new tunnels for other domains not referencing or linking like this? Or is it not a problem?