I just ran into an issue that might have been causing an unexpected problem. On initial install I set the TV password with a 16 character string with no warnings. I was able to connect to the login screen but after signing into the (debian-linux) desktop my session would timeout.
I purged the TV-host and reinstalled and configured from the command line. When setting password I got a warning of a 12 character max length.
Debian Linux 10 & TV-host 15.11.6 x64
Windows 10 & TV 15.11.6