StellarMate X creates its own virtual display screen so it is accessible via VNC without any monitors connected. If you connect an external HDMI monitor to StellarMate X, it attempts to clone the internal display to the external display. Sometimes this results in the external display stuck on StellarMate X loading screen. The system is fully usable nonetheless. There are two methods to resolve this:
On startup, StellarMate X wil attempt to duplicate the internal virtual display to an external HDMI monitor. You can configure the Display Configuration from StellarMate App or VNC. In VNC, follow the steps highlighted in the picture below to duplicate the VIRTUAL1 output to your external HDMI monitor.