Reproducible in Unity 2021.3.5f1

1. Open the attached project
2. Open Device Simulator and Game
3. Click in Game - Debug Log is printed once
4. Click in Device Simulator - Debug Log is printed twice

Expected behaviour: Debug Log is printed once in both cases

There is a  repro test project:

https://drive.google.com/file/d/1O5XY_h4xO5hUd2PfsyarmBdl5MuAdyEa/view?usp=sharing

Here is a video illustrating the issue:

[https://drive.google.com/file/d/1fTcqmZAiLmevxH-rO0RkwFQKpf1upjOG/view?usp=sharing]

(for some reason I couldn't attach it to Jira ticket)

Test code:

void OnGUI()

{

   if (Event.current.type == EventType.MouseUp)

   {

       Debug.Log("OnGUI :: Mouse Up!");

   }

}