See if the fuse is loose. If so, you can bend the fuse blades very slightly in opposite directions to get a tight fit.
If you're on shore power, the smart light and other 12V DC lights should be getting power from the power converter, even if the battery is removed.
If you have auto levelup, cycle the control panel buttons to read voltage at the levelup panel. On shore power, disconnected from the tow vehicle, you would normally see 13.2 - 13.6V DC on the display. If it's lower, perhaps below 12V, you may have a low battery because the power converter isn't working. As the battery voltage drops, miscellaneous problems will show up.
There's a diagnostic flowchart in our 12V Block Diagram and Troubleshooting guide, located in
this folder.