Leak inside from ceiling, 2011 Monaco Knight

Also check the HVAC roof unit for condensate that normally occurs and is to be evaporated or drip from the condensate pan. That pan sometimes overflows due to slope and plugged drip holes that build up with dirt and leaves. When it drips due to said condition, the overflow gets into the inside of the HVAC unit and flows into the roof ducts and comes out what ever place is closest and lowest. Under the roof HVAC is a gasket that may also be not snug or completely flattened due to age or over tightening which is done from inside four corner snugging bolts. If that's the case, new gasket(s) may be needed, which are done by removing HVAC unit and wires and removing old gasket(s) and placing new gasket(s)a job done by experienced installers. At the point of removal the inside roof area can be seen and any additional repairs done if leaks have allowed mold or subroof to be damaged.