When our two picky babies went off feed, we changed things up.

They were being fed f/t in a separate feeding tub from day one. At first, they would both strike and eat almost right away. Then, over time, they stopped striking and would just eat the rat if it was left in the tub. Eventually, they wouldn't even do that. We would leave them in their tubs for hours with the rat and nada. So finally, we decided to switch over to feeding in their cages. They still wouldn't strike, or even eat right away for that matter. But, when left in the cage all night long, no rats in the morning! My 3-year-old hadn't eaten for a 77 day stretch at one point. Now, he eats every time I offer him a rat. Maybe you can try this technique?