Lights out

So are lights will not work in our 2019 T@B 400 and we have checked g to uses and breakers which . I am Wondering if it has something to do with the inverter switch. However the light above my dinette and next to my bed are both working. We were plugged in to shore while camping this last weekend, and when we came home and started cleaning the lights did not work. Can someone please tell me where I can find the inverter and if it should be off or on. We have ability to hook up to shore here while we are not camping at home and like to leave it hooked up and run our air conditioner to keep it cool. Thanks for help!