A pinkie mouse for an RTB? I'd imagine the snake is ignoring that prey because it's way way too small to even consider it worth the snake's time to bother with it. Glad you've found a much more appropriate sized prey item. Give the snake a few days to a week of not being fussed around with at all (other than basic cage maintenance), then try a nice, quiet evening feed. If this is an f/t prey item make sure it's fully warmed up (especially the head and belly) and use tongs, hemostats or long tweezers. RTB's even young ones can have very long strike ranges and you don't want a feeding error/accidental bite if you can avoid it (not nice for you and will upset the snake and likely put it off feeding that week as well as the possibility of it losing a tooth or two in the process).