Force feeding right now is out of the question additionally force feeding is for hatchlings that have never taken a meal and cannot even be assisted, and should ONLY be done as a last resort preferably by someone experienced.

The more details you will give the better we can help you try to narrow it down and see if something can or need to be done.

Have those snakes ever took a meal for you?
Do you feed inside their enclosure?
How big are your snakes (weight) and how old?
What size tub do you provide?
Do you handle them if so how often?
Do you provide hides if so how tight?
What type of hygrometer / thermomether do you use? Are they digital?