OnMouseEnter triggering on wrong object

Hi all,

I'm having an issue where OnMouseEnter seems to be triggered on wrong object. I have a MonoBehaviour class that contains OnMouseEnter method that changes color of object it is attached to.

 public class InventoryCell : MonoBehaviour
 {
      public void OnMouseEnter()
         {
             Debug.Log($"Enter {gameObject.name}");
             _material.color = _configuration.HoverColor;
         }
 }

This class is attached to all objects representing inventory slots. However, when I hover mouse incorrect object changes color. It's like there's some weird offset being added to mouse position when calling the event. The further from center of the screen the mouse is the farther object OnMouseEnter is called
Doubled checked and I have all colliders setup correctly, none of them are interfering with one another (in video you may notice that collider scale is 1.05 - it is made so to fill gaps between slots, changing collider scale to 1 does not solve the issue). Worth mentioning, objects being hit are rendered by overlay camera not base one.

I only wrote about OnMouseEnter, however, the same behaviour is happening with other OnMouseXXX methods as well.

Uploaded video recording of the issue here: https://1drv.ms/v/s!Ap4-t2P-IgziiNUlWkyNNYEjp8QbIQ?e=tSAkG6
Any idea what may be the cause of this?