That is definitely odd behavior. Multiple sessions is a server side setting, so your Linux system shouldn’t be able to do that without windows being ok with it. As for the resolution issue, it might be a config issue in your client. Give another client a shot, or see if there’s a way to configure the client to use smart sizing. I can’t recall which app I use on my system, but I can’t say I’ve ever had an issue with scaling between connected and remote connected sessions.