Missing vent cover all winter spring

I figured out they do turn, very hard, and come off then the base is held on by 2 screws. Got them off. Started the drying out process. Surprisingly not very wet. Was able to take off the shroud to the bathroom roof vent and get between the ceiling, insulation, and roof really well that way. Was able to reach around up there and and feel around for any moisture too. having the vent there allows me to see up there good too. Was using a couple blow dryers on low heat under close supervision to blow air through the area. New vent is supposed to come today and I plan on drying things out from the top by blowing air down too. I think I lucked out by having a low spot in the ceiling right in the bathroom area near the lights. There was only a small amount of water pooled in the lens cover of the lights. No other "pools" but some slight dampness. Took off some other light covers and did some inspecting and couldn't find any other damp areas.