DNS record interfering with all ".domain.com" sites instead of just routing "remote.domain.com"

I have a remote desktop that I am trying to connect to via Microsoft Remote Desktop. I can use the IP address of the remote desktop while on our network to connect to it, but if I am off network I have to use "remote.domain.com" to connect to it. Both work fine, however it's a slight annoyance to have to change the PC Name from one to the other depending on what network I am on.

To allow it to work with "remote.domain.com" on and off our work network, using the Mac Server application I added a new host name "remote.domain.com" to route to the IP address. While this does work, it creates other issues. We have a lot of sites that are "something.domain.com", that all the sudden become unavailable when I add that host name, but visiting "remote.domain.com" brings up a generic Windows Server page (which makes sense). It's like the host name that we added is acting as "*.domain.com". Could someone explain to me why it's interfering with all the other ".domain.com" sites and not just dealing with "remote.domain.com" and how to fix this issue?

Thanks!