My first terminal server set-up I seem to remember putting using in security group i.e. TS_Users and adding that security group in Terminal Services Configuration > Connection > Properties > Permissions > with Guest access. Last one I tried adding to TS_Users (and individual users) to RDP Users Group in AD and that did not work, Adding TS_Users security group to TSConfiguration did not work as it did before. I ended up having to add each user individually to Terminal Services Configuration with Permissions.
I am now setting up another terminal server. What is proper way to grant users access?