Inconsistent behaviour with mouse events

Unity Engine
1

Hello!
I feel I’m going crazy. OnMouseDown (and relatives events: OnMouseDrag, OnMouseEnter, etc) simply won’t trigger on my project (let’s call it Main).
What is worse, I have tried creating a new project, doing the same setup and it does work on it (called this project Test).

Here’s my code, and what I tried so far:

using UnityEngine;

public class Draggable : MonoBehaviour {
    void Start() {
        Debug.Log("start"); // <- This triggers
    }

    void OnMouseDown() {
        Debug.Log("mouse down"); // <- This does not
    }

    void OnMouseEnter() {
        Debug.Log("mouse enter"); // <- This does not
    }

}

Simple enough, should work.

  • Both in Main and in Test, I’m just using a default white square with the same dimensions and position (Z axis position in both is 0), created from GameObject → 2d Object → Sprites → Square
  • Both have a BoxCollider2D with default properties (0,0 offset; 1,1 size, etc). Switching to regular BoxColliders still won’t work on Main (but it does still work on Test)
  • Camera is default in both (Orthographic, depth is -1, Z Position is -10)
  • As per the documentation, Physics.queriesHitTriggers is set to true in both (the default)
  • Everything is on the Default layer
  • Nothing was changed in Project Settings → Physics/Physics2D that could mess up with the raycasting. As mentioned, QueriesHitTriggers is true.
  • There is nothing else in the scene but the square and the camera that could block the raycasting.

Creating a new scene in Main, and putting just a camera and a square still doesn’t work, so this is leading me to believe it is some global configuration, rather than something wrong with the script or scene setup, but I cannot think what could that be, nor I’m finding information googling on requirments I could be missing.
At this point I’m close to just moving everything in my Main folder to a new project, but I would rather avoid that.

Any ideas?

Thanks in advance

2

For whoever comes around this in the future:
It was the New Input system. Crazy that there is no warning on the MouseEvent documentation warning you of this. There is only a small aside on the Known Limitations of the InputSystem
Crazier still that there is no easy replacement for it.
Workaround solution is to enable both inputs systems to run at the same time. Which is kind of stupid.