LP Tank Selector valve

Hey Guys,
Is it common for the selector valve on your LP tanks to go bad? I recently had both tanks filled, I keep the bottles turned off when not in use. Have only used the camper once since having them both filled. I just turned on the heat, the heater is working, however the "full indicator (red and green color) is showing red (empty) for both tanks, but the heat and stove top are working, so there is obviously gas in the tanks. Was wondering if the indicator can get stuck or go bad? Thanks for the help