You are going to have to develop a LOT more patience with incubator learning! I am on lockdown with my second batch. First was analmost total failure with a still air LG. Now we added a fan, weatherstripping, another thermometer, washcloths rather than sponges on lockdown and isolating the location better.
It's an art in addition to a science, so it's not as cut and dried as the instructions would have you think. I am glad I have a cheap source of experimental eggs ( mine) before I invest in some *real* eggs!
My personal opinion is that the actual precise temp probably doesn't matter as much as the range of temps. I fussed yesterday at lockdown because it took HOURS to get back up to 100 after I removed the turner, candled everything etc etc. Then you hear about eggs that had electricity out for a day and still survived.
Patience, practice, eventually, you will learn.
At least, that's my mantra!