I had one hatchling that was beyond frustrating last year. Didn't even take to assist feeding easily.
It showed the most interest to mice hoppers, but acted "afraid" of them. Whether they were f/t, pre killed or worst, alive!
I kept trying. One day I decided to put all the babies on substrate instead of paper towel. Put them all on Reptile Prime, which is a soft coco coir that is not as fine as Eco Earth, but not as coarse and chunky as Repti Chip.
Now..it could have just been coincidence but that little one seemed to like the dark substrate and the ability to be "lie low" in it. The very next time I tried a pre killed hopper she showed a lot of interest, but didn't go for it. I put it with her and left. (had previously tried that and didn't work then).
To my HUGE surprise and GREAT relief the hopper was gone when I checked 2 hours laterA week later, same thing. She showed interest but was easily spooked. I left the pre killed hopper and she ate it up fairly quickly.
A week later she STRUCK and wrapped the pre killed hopper. What a relief. We turned the corner. After a few more meals I re-homed that snake and she continues to do VERY well and is much loved.
I have to admit, I came close to giving up on that one. Assist feeding is relatively easy, and I don't worry about it much. But this hatchling wanted nothing to do with that or anything else food related. It ignored all feeding attempts and fought the assist feeding.
Don't give up, but don't get to rough.
If that one is on paper towels, put it on dark substrate. make sure the tub is small and private (not open view all sides). Let it settle in the new setup with the substrate and then offer a pre killed hopper. If she/he is interested but shy, leave the hopper near her and walk away. Don't give in to peek until next day or at least a few hours later. Offer it late at night.
Good luck !