I cannot stress how important it is to calibrate your thermometers because thermometers are known to be wrong/being off one or two degrees is a huge amount when it comes to incubating eggs.I have read about keeping it lower too. So did you buy the extra fan for yours? What temp do you set it to? How do you increase humidity when you need to? Mine doesn’t want to increase easily.
I do not use a fan.
When I need to increase my humidity I just open the lid and pour a little bit of water in.
I actually just hatched some eggs two days ago, all hatched, at only 38% humidity.