Currently on macOS and ChromeOS it's impossible to navigate the area using panning or scrollbars of the session if the session is larger than the client window. There is no option to navigate by either the panning feature or scrollbars.
Upstream: https://github.com/novnc/noVNC/pull/1311
Fixed in upstream and vendordropped into ThinLinc: https://github.com/novnc/noVNC/commit/e52a278ed7aca2f2c0831e3ceabefcdb39581620
Verified on nightly build (r6392), tested: * Windows 10 - Internet Explorer 11 - Edge 44 - Firefox 73 - Chrome 80 * Chrome OS 77 - Chrome 77 - Firefox 68 * Android 8.1 - Chrome 80 - Firefox 68 * macOS 13 - Chrome 80 - Firefox 71 - Safari 13 * iOS 13.3 - Safari 13 Works well on these.