Wayland/KDE/Debian-testing/Nvidia525.60.11 – Monitor not receiving signal after turning off/on (likely also from sleep): instead of disconnecting/reconnecting the gpu-monitor cable, which wears out connectors, simple press ctl-alt-F2 to create new session login that sends signal to monitor. Once monitor is active, press ctl-alt-F1 to log back in to original session. This bug existed in X11 a few months ago.