So sorry about the foxes in your hen house. I've lost6 of mine and my pen and hen houses are totally enclosed. Couldn't find where they got in but it breaks an animal lovers heart. Have you set live traps?
Humidity should be around 57 to 60. Do you have room for another water container. Make sure to add warm water. Not sure what to do about the temp fluctuations. If you change to 100 watt bulb it will probably be too high during the day depending on your temperatures. Maybe you'll get bbetter...
Set 12 Silverlace wyndottes on March 10th. On day 10 discarded 5 clear eggs. 3 more were iffy. Hopefully they will hatch. Having trouble with egg turner and humidity. Got turner working. We'll see what happens. Also set 10 more on the 10th in a different incubator. We'll see.