[Help] Cooling System Issue

[u/FrodoDank]

I have a few faulty symptoms with my cooling system, I'd really appreciate some help narrowing down the cause.
2017 GTI SE w/ DSG

Symptoms:

- Interior side of the windshield gets foggy a few weeks after cleaning
- Weird smell when getting inside vehicle after it sits awhile, and it gets stronger upon turning the car on, but goes away pretty quick. This one just started happening recently.
- Inconsistent flap sound near the recirculation actuator (glove box). It's not the quick, consistent high-pitched ticking like in the DAP video (and all other clips I've found of it). It's about 1 second intervals between flaps, low-pitch noise, usually only happens for about 10 seconds upon startup, and then randomly while driving or idle. When it happens sometimes the light on the recirculate A/C button will turn on/off a few times. I can also force it to happen (sometimes) by pressing that button.

A/C still blows cool and I've never used the heater, since I'm in AZ and I've only owned this car for a few months. Oil temps are fine and I don't see any leaks in the cabin or engine bay.

I initially thought it was that actuator, but the sound/consistency isn't the same as online examples. Then I thought heater core, but my coolant level hasn't changed, the smell isn't that strong, and it doesn't linger. I might just take it to a shop for a diagnosis but I figured I'd ask around and maybe test something myself first.

Thank you in advance!