It's the heat in Leander -
Seriously, this sounds like a broken wire / loose connection on the circuit that feeds the ceiling for the main coach and kitchen island. I would probably get on the ladder and start at the island to see if you can see where the connection comes in from the ceiling. You might also check the back side of the switch to see if there are multiple connections at that point.
I've not checked those connections on mine, but I'd guess that the wire that feeds the ceiling also runs across to the overhead lights at the island. Really strange that the problem would appear overnight.
According to the wiring guide the wires will be green & white 14 ga and should have a number stamped on them (probably 3 - maybe 4) for the zone in the trailer.
Good luck - let us know what you find!