Had something almost identical happen back in 2019 - my lurcher refused to budge from the hallway for a solid four hours, just staring at the ceiling. Dogs are genuinely remarkable early warning systems and I don't dismiss that behaviour lightly.
A few questions worth considering before jumping to conclusions:
What time did it start? A lot of genuine cases cluster around 2–4am, which is interesting in itself, Did you notice any temperature drop inside the house? Even subtle ones, Any smell beforehand? Some people report a sulphurous or metallic odour
Obviously the rational explanations - foxes, cats, thermal expansion of roofing materials - should be ruled out first. Cardiff gets urban foxes badly and they sound unnervingly human sometimes when they're moving around up there.
That said, the dog's reaction is the detail I'd focus on. Animals don't perform. If yours refused to go out until morning, something was registering on senses we simply don't have access to.
Worth setting up a basic audio recorder outside overnight - something like a Zoom H1n on weatherproof mount - to catch any repeat visits. Even if it turns out to be mundane, you'll have eliminated the obvious.
What kind of footfall pattern was it? Rhythmic or irregular? That distinction matters quite a bit when trying to work out what you're dealing with.
