Amber1980 are you on a Windows PC or phone? If Windows PC what version/edition of Windows? You can find this information out by clicking Start and type the word WINVER and press enter. View attachment 225831
Yes, 1909 should be work as I was using the CC app on 1909 just fine. As far as the connection issue chances are you have some other software installed on the computer that is not allowing the traffic to go through. Such as a firewall or anti virus. I installed Windows Server 2019 Evaluation (fresh install) on a virtual machine and try it just to see if it will connect and it does but no members show up. Strange.