I'm necroing this thread cause it's locked: https://www.construct.net/en/forum/construct-3/how-do-i-8/two-objects-pathfinding-not-138879
If you add a pathfinding / Los obstacle to a specific instance of a family, that obstacle will be added to all members of the family. So it's not possible to have the same LoS behavior have different obstacles among instances.
This is annoying because I want certain objects under a family to have different obstacles. (e.g. crawling enemies can't go up stairs).
A work around is to have a second LoS behavior which you only call after checking the family LoS, if enabled for that type. I get the performance, but this does feel like a bug. You wouldn't need different maps for every objects, just every variation of obstacles.
Just an FYI. So stuff like this would actually apply to all NPCs, breaking their LoS behaviors.