Collision detection

Why is collision detection sometimes not detected. In the same project, I edit the hit box of two objects, but only one of them will detect collisions when it collides with objects.I don’t know what the reason is. Please help me

we need a video or example of the bug happening(guessing its a bug)

When you have several identical objects on the scene, sometimes GDevelop doesn’t know which instance you are talking about in your conditions/actions.
Well, more precisely, it assumes you meant that specific instance over there, when in fact, you meant another instance, or any instance of that object.
All potential confusions must be cleared.

Maybe that’s the issue here.

Doing my game Paper Plane, i had a problem with HitBox due to me and not to GDevelop.
The result was one bad collision between 2 objects because my first object was not a simple rectangle but a rectangle with square holes in the object.
The solution was logically to adapt the HitBox creating n boxes for the collision.
Perhaps Guoming has this issue.
But we are blink if we haven’t no more details (screen copies of objects and hitbox(es) and of course, more information of the events)