@Deluxe thanks for sending this through. Is this log file the result of a failed session? There’s nothing in there to indicate anything wrong unfortunately.
It’s strange that suspending the server fixes the issue, I’ve never come across this before.
I wonder if it is the desktop environment causing issues here. Have you tested using another desktop environment, such as XFCE or MATE? These are already configured by default in ThinLinc, so all you should need to do is install the packages from your distribution repository. These are generally much better DEs to use for remote desktops than GNOME 3 anyway; see “Which desktop environment should I use with ThinLinc?”.