Windshield fog on inside

hello.... 2015 tacoma fact windshield and I have noticed a couple times that when it is cold or humid And my truck is outside for 30 mins or more my windshield if fogged or moisture on the INSIDE of the trucks windshield. Center of the dash ( directly above the radio about 4inches from the bottom). I came out the first time and put my finger to the windshield and I can wipe it away. As soon as I put on the defrost it goes away. Happened this evening so after I put the defrost on and it went away I moved the air direction to the front vents and I didn't fog up. I am assuming there could be a leak maybe but it's in a weird spot. Wondering if I'm missing something that I'm not aware about on these trucks or if this a common problem or isolated to mine. Thanks in advance

 

Normal in cold weather.

 

Simple. Residual humidity in cab condenses on cold glass.