"..If ESET is installed through an RDP session, the firewall is disabled to prevent the connection from being disconnected.."
This is not the case - unless the incorrect installer may have caused this - as soon as the install completed the RDP session was dropped.
On the laptops incoming RDP sessions were not connecting even though in the ESET config port 3389 was open via svchost.exe
Once I disabled the Network Protection manually RDP sessions were able to get through.
I'll get the settings changed as you suggest, but this will require another on-site visit now.