Intermittent windshield fogging.

[REDMIST]

2023 RAM 1500 5.7 etorque hemi with 39k.
Lately anytime I try to use defrost/de-fog it will fog interior glass. Sometimes so bad I can’t drive. The other morning it was below freezing and the inside of the windshield was covered in frost. After finally getting it defrosted, it would still intermittently fog, then de-fog and then fog again.
Anyone had this experience? Any ideas as to what’s causing it?

 

[Dean2]

Did you have it on re-circulate. That will fog windows fast. Use outside air and make sure the A/C is on to dehumidify the air. You see fogged windows here all the time. The new Canadians think inside air heats the car faster, which it does, but it fogs the hell out of the windows because you aren't getting rid of the moisture.

Cracking the rear passenger window a bit will also help defog the inside.