Cab leak... any ideas?

I'm wondering if anyone here has had the same issue I've been having lately. First I noticed large amounts of condensation on the inside of the glass in the cab all the way around, both sides, windshield, back glass, and sunroof. Went to install new floor mats and when I removed the old ones there was white mildew formed on the carpet in the middle of the backseat (I'll include pictures). My best guess is there's some kind leak into the cab in the floor, maybe a drain plug went bad? Dealer says it must've been a spill that got covered during the detailing process but I doubt it, I've had the truck for three months and just noticed the condensation starting under a month ago (specifically its a 2018 trd sport double cab). For now I bought one of those Damp-rid things and hung it from the back of the headrest, gonna see if it'll go away and if it comes back. Any other ideas?

 

Check for the cab mounted (3rd brake light) recall, it should have already been done, but maybe not, or it wasn’t done correctly.
You can run the VIN on Toyota’s site and see service history, so you’re armed with info before you go to the dealer.

 

Third brake light... there is a bulletin on this..

Sunroof drain plugged... have my wife's Impreza carpet all torn out right now because of this one..

Leak at front vent under cowl... previously repaired this issue with wife's car...