Oh dear its so frustrating isn't it. I bet you'd just settled in to relax too

You know it could be something completely unrelated to whether he has a routine or not. I'm pretty sure our unsettledness at bed times recently was due to a number of things - primarily teething and just all the big stuff happening for their little bodies developmentally. It doesn't help that they are things that are mostly out of our control and we just have to roll with. Try not to analyse it too much, you just end up doing your head in even more in my experience.

Good luck