I thought of one more thing: This could be remote client causing this. I almost exclusively use KRDC client to log into this VNC server, so maybe something is there which cause this. But I am willing to change a VNC server rather than debug a client - simply because a server should never crash.
-- With kindest regards, Piotr. ⢀⣴⠾⠻⢶⣦⠀ ⣾⠁⢠⠒⠀⣿⡁ Debian - The universal operating system ⢿⡄⠘⠷⠚⠋⠀ https://www.debian.org/ ⠈⠳⣄⠀⠀⠀⠀
