Lots of fish, including eels don't always eat after getting moved to a new environment. Give it some time and don't worry, as long as your eel is healthy, it won't let itself starve to death. It can especially take time if you're trying to tong feed if it wasn't already fed that way.
That being said, try using a garlic additive, it can help with a feeding response. Some say it can also help with internal parasites long term, but some also say long term it can harm your fish as well.
Also try switching up the food, shrimp, clam, scallop, squid, krill, crab if you feel fancy. It may be a preference thing, took mine ages before it would eat anything but shrimp.
Worst case, source some live food like ghost shrimp, any kind of marine shrimp, sexy, Peppermint or what have you would also work, but run the risk of teaching it CuC are edible and transmission of parasites if not properly quarantined. I believe an eel swimming around at night means it is actively hunting and searching for food, so give it some time and you should be alright.
