I'm seeing some regression where if I reconnect to a session above a certain size, then the session will immediately be resized to something smaller. This is most obvious if you reconnect to a maximized session. On my test machine this is 1920×1131. After reconnect, the session is instead 1440×839. The resized size seems to vary a bit. One theory is that there is something remembering and older size of the window and is trying to restore that. I have not investigated when this started to happen. It is unclear if it is caused by an upgrade of ThinLinc, or the desktop environment. Seen with ThinLinc 4.15.0 on Fedora 38 with GNOME on Xorg.
Perhaps this is another variant of bug 8199?