Another question about humidity

I can keep humidity in the 50-60 ranges with the lights on and my exhaust fan which is thermostatically controlled.
My problem comes at dark time. With lights off the humidity creeps up to about 80-85%. My humidifier doesn’t even come on now that our weather is more humid so that’s not an issue.
I’m running 20/4.
Will this relatively short spike in humidity pose a problem?
They are still pretty small at 9 days old.

That’s auto flowers ? But I’m having the same issue when lights goes off , so I put my 6 inch duct fan on a timer with lights , hoping that helps , but I am running a gro bro CO2 bucket , and I’m wondering if the ppm from the C02 is what causing a spike in my humidity when lights off . So far plants has not show signs of any issues , and I hope they don’t , being that one auto is less than 3 weeks of finishing .

Yes autoflowers. I should have mentioned that.

The spike in my humidity has not cause any issues as of now , but it does make them drink more water seems like , but that can be they in final phase of flowering . But I’ve noticed a spike in my humidity just today , so I put my duct fan on a timer with the lights . Now my inline cotrollable fan is on max , and I’m wondering if I turn it down when lights off will that help , but in my research if I find a solution , I’ll definitely let you know , are I’ll post it in my thread (first time growing auto’s blueberry and amnesia haze ) , but I’m definitely looking into how I can get more control . I’m also growing 2 auto’s , and you have 6 , man it’s gone get crowded in there once they start branching out . I had to do a lil trimming , but don’t get snip happy are you will stress and stunt them , just remove lower leaves only and crowed area slightly .

I’m gonna cull them down to 3 or 4. The extras will go on the balcony although it’s not gonna be as nice for them outside. I don’t want to get rid of them.
I live in southern California coastal so even in winter it’s not too harsh. Getting eough sunshine will be the issue.

But if they do , they will definitely put out .