Loosing focus on webGL when interacting with ui elements

I posted question originally on stackoverflow with no luck.
https://stackoverflow.com/questions/63106622/loosing-focus-when-interacting-with-unity-ui-on-webgl

Simply saying when I click on ui element to close the canvas then I have to click again on the webgl screen to take unity take back control of pointer. I am wondering if that is a unity bug?

 

Solution found.
Create new class that inherits from Button class and override OnPointerDown method.

public override void OnPointerDown(PointerEventData eventData)
{
base.OnPointerDown(eventData);
Cursor.lockState = CursorLockMode.Locked
}