Two foot Brazilian rainbow boa feeding question?

So my new brb was just fed for the first time in a seperet tank from the enclosure and it ( person who sold it to me kept saying it was male and then female) striked the hopper perfectly twice but then didn't eat it totally there was no history of Bad feeds before and I watched it eat perfectly.....could it be it is about to shed? It has been hiding more and burying itself in the substrate or does anyone have an suggestions on tips? I plan on feeding frozen and thawed it's whole life so please keep your opinions about that to yourself and please DO NOT give me pointless greif about feeding in a sepret container