from my experience when snakes kill a prey item and just leave it, it tends to be too soon after their last meal. i would tryin giving them an extra few days so they build up the hunger drive and then they should accully consume them. also this might be a good time to switch to pre killed as it can be risky feeding live. best method i have found for boas that act like yours is to have a killed prey item and dangle it by the tail (i think your supposed to use tongs or forceps but i just use my hand). your hand shaking while holding it will normaly be enough movement for a snake who normaly eats live to attack the mouse. also this type of feeding almost always results in a bit on the preys head which makes for faster and easier consumption.
good luck