This display should work, but it needs to be configured before use. You will need to look for a file to load onto the screen, this file needs to match your model number. Once it is loaded on the display you should be able to see the updated information.

The best resources I know of are on Facebook. Look at these groups: Nextion Screen for MMDVM Hotspots and Nextion – HAM-Radio Screens.

You will find instructions for updating your display on these groups.

You also mentioned issues with your device not booting up. Do you think this is happening because the display isn’t getting updated, or because you can’t connect to the dashboard?