You can try to change the resolution on the Meet S to adapt to the 4K monitor. Here are the steps:
Step 1. Connect Meet S with another display with lower resolution, then connect a mouse to the Meet S.
Step 2. When the rooms page shows up on the display, click the version number for 5 times, and long hold it for the 6th time, then the Meet X will enter the Android system.
Step 3. Then find Display-HDMI option, then you can change the resolution. The page might be in black, so you need to hold the mouse to see the words on it.
Step 4. Choose the lower resolution, for example, 3840*2160 25HZ, which can work with 4K display.
Step 5. Right click the mouse, and the system will be back to ezTalks Rooms page.