Yes, it very much is a trial and error kind of thing. the 65% goal was just to make sure we can reach lockdown levels.
I thought we had it last night. It was steady at 99F and 65% all day. I came home for work and it was 97 again. So I covered the whole thing with a towel. And half a hour later it was reading 95F @.@ the heck, the towel was supposed to help it warm up, not cool it down. So weird.
We even used a stronger watt light bulb, and it still wants to sit at 95 or 97.
I'm going to pull my hair out over this thing.
I wouldnt worry too much about final humidity - once those eggs start pipping - humidity goes up massively.
It does seem odd what’s going on your temperature though!
The only things I can think of are.... do you trust the thermometer? - do you have a fan in there or could you have hot & cold spots? Do you have an auto turner? I know the temperature in mine varies as it turns... but it averages out ok - but it means I have more than one thermometer in there - but that also helps with me worrying about whether one of them isn’t reading accurately.
Broody hens are so much easier!