That sounds really tough, and I totally get how bedtime can turn from a cozy moment into a battleground. My kid went through a similar phase where any change in the bedtime story routine was a no-go. What helped us was introducing a "story jar" with slips of paper that had different books or even story themes written on them. We’d draw one together each night, so it felt like a game and gave them some control without sticking to the exact same story every time. Also, sometimes prepping them earlier in the evening about a possible change helped ease the transition - like, “Tonight we might read a new book, but we’ll save your favorite for another night.” It’s definitely a phase, but if you notice the rigidity creeping into other parts of their day or causing major distress, it might be worth gently checking in about any worries they have. Hang in there!