Setting tilemap collision mask to a pathfinding obstacle seemingly sets the entire bounding box as the obstacle, instead of the collision. I think it has been like this since at least 2016 (judging by another forum post), is it still like that or is it a different problem? If it is still like that, is there a work around (preferably without manually setting the collisions)?
This has nothing to do with Tilemap collision mask objects, to be clear. The pathfinding behaviors see obstacles based off their entire bounding box, not the collision mask.
You might check the Navigation Mesh Pathfinding extension, I think it interacts with collision masks.