Had something similar last year out in the Lincolnshire countryside. Three nights, same pattern, like deliberate footsteps rather than a squirrel or fox scrambling about. Animals are erratic - whatever was on my roof was methodical. That's what got me.
Set up a Wyze cam pointing at the roofline on night four. Nothing showed. Which is almost worse than catching something, honestly.
Few things worth considering with yours:
Timing - same time each night, or random hours?, Weight - did it sound heavy, or more like something just present but light?, Reaction from pets/local animals - my neighbour's dog went completely silent those nights, which was unusual
The Men in Black crowd would say heightened surveillance often precedes certain types of activity, but I'm not going that far down the rabbit hole just yet.
Most people jump straight to ". Pigeon nest". Or ". Thermal expansion". And fair enough, rule the boring stuff out first. But three nights straight with the same pattern? That's not a pigeon.
What's your location like - rural, urban, near anything unusual? Makes a difference. Anyone else had roof activity that didn't have a clean explanation? Genuinely curious whether this clusters geographically.