that's right; i apologize for forgetting. that was the right course of action.
TBH ive seen weird preferences like you're describing, mainly with my picky two: Yellow and Spaghetti. Spaghetti let's me know if my rats are too "old" for her, but she'll sometimes eat them anyway if she's hungry enough. my others eat so i know they're not bad, but i guess she's a diva.
you very well might have a mouser. i really wish i had more insight to help but i don't.i hope others can help you once again.
EDIT going back to my old rats: i had a freezer mishap and had to replace my whole stock. Spaghetti was being a usual diva with the older rats i had before the fail. she didn't eat until i offered from my new stock. it does happen.