I am using x11vnc to successfully connect my Pi4 to my Panasonic TV where I watch movies for perhaps 1% of the time, 99% or the time I use the Pi4 headless via my laptop for other purposes.
I have encountered a problem (well maybe two) and I suspect it may be a problem with the TV end but am unsure.
If we are watching a movie as described above and decide to stop it to do something else and resume a few minutes later and either turn off the TV or just change which HDMI input to use before we return to the movie, we cannot return to the HDMI signal from the Pi4.
It appears that the TV 'forgets' there was a signal after only a few minutes and cannot resume. The signal does still exist as I see it via VNC.
The Pi has only just been set up and still has a USB mouse and keyboard attached. Both will soon (hopefully) be removed. If I move the mouse pointer the HDMI immediately connects and the movie is back. The option -forever is in use.
But, moving the mouse has the undesired effect of cutting the VNC connection and a connection is then refused until I ssh in and reboot which is not really a viable method of resuming.
As I suspect it may be the TV end, I have asked a question in the avforum too.
I am wondering if RealVNC will be recommended