Right so this is exactly the kind of thing that gets dismissed immediately but animals don't lie, that's the thing. Dogs especially. Mine did something similar back in 2019, refused to go past the back gate for nearly two days straight and I never did find out what had spooked him.
The roof detail is interesting though. What does the walking actually sound like, is it rhythmic or more random? Because there's a massive difference between something pacing deliberately and something just moving around. I've read a fair few abduction case studies where witnesses describe sounds on the roof the night before a missing time episode, which I know sounds like a stretch but once you've looked into enough of these accounts you start noticing the patterns.
Did you check the roof in daylight? Any marks, displaced tiles, anything like that? That'd be my first port of call personally. Get yourself up there with a torch and have a proper look before you do anything else. And keep a note of the date and time, these things matter more than people realise when you're trying to build a picture of what's happening.