Rule, yes probably. Actual enforcement is a different matter, and varies a lot. There are places I know are too remote to realistically enforce the rules, because there’s no other way to get there but hiking, and local governments aren’t likely to be finding money in the budget for patrolling park rangers or cops on those trails every single night.

I find that if a trail is anywhere near a body of water, enforcement is stricter. That’s probably because they don’t want to be legally responsible in any way for someone drowning in one of their parks.

I hope you find a pleasant place where you can hike in peace!