CrazyHatchingLady
Chirping
63 to 70 percent for the first 18 days? That's very high, actually. Are you at a high elevation? Did the air cells look good when you were candling them, like they were developing correctly, as this chart shows?
I'd never have humidity that high, over 60%, until lockdown. I keep it at around 30% for the first 18 days, and then go to 65% for lockdown.
70% is plenty for lockdown, you don't need to go higher. Why do you think the one that you have hatching has dried out? Can you post a picture?
If you do need to do an assist, follow this guide: https://www.backyardchickens.com/articles/guide-to-assisted-hatching-for-all-poultry.72886/
Oh no during incubation it is 47-52% usually. I have eggs I ordered that was between this at incubation at lockdown 60 to 70% and did fine. Right now I lowerd my temp a little and they stopped drying out. Plus I used the coconut oil I saw in your article. Ironically I don't usually have what I need but this time I did. It seems to working really well and they two that started to hatch are doing much better.