What is your recirculation setting, auto? If it is in internal recirculation you will have issues with fogging control and lots of air flow, warm and cold as it 'clocks' to clear the misting.
Some HVAC basics. I'd not slow the fan speed, as it can mean you are taking the whole system out of full auto, then it is in semi auto and possibly fighting for levels. Let it settle itself, as it will run minimum fans speeds where possible.
If you are fogging, then you either have some issue, (water ingress) or need to set it up better. I assume you using the full auto, snowflake on? If not try it switched on, using full auto, to stop it needing lots of air flow to clear the mist.
It pumps in more air when the fogging sensor detects misting, and will change temperatures as it goes to more extreme levels to clear it.