Actually, this sounds fine. 30% is what I keep mine at for the first 18 days, and if the humidity stays at that point without me adding water, then I don't add water. Any higher than that and it my area my embryos would drown. How do the air cells look? Did they develop well?
80% might be a touch high. Personally I'd drop that to around 65 or 70% if you can. Higher can make it harder for the chicks to dry off after hatching and isn't really necessary.
If today is day 19 or 20 and it was only at 30% humidity on day 18 and possibly day 19 I was wondering if 30% humidity is too low for one and maybe two lockdown days. So a little extra humidity for a day or two might not hurt. Just wondering. Hope you can follow that.