[Xrystal]

Unfortunately OnEnter and OnLeave doesn't involve a mouse button being clicked. The frame is interactive.

However, you can register for OnMouseDown or OnMouseUp and check for a specific button being clicked to interact with the frame only on left click. However, whether that allows you to click behind it with the right mouse button is another thing. As you have been doing, all you can do is try things out. Which by the looks of your post you have tried to do.

Hopefully if someone has done what you want they can either point you to an addon that has it working for you to look at or can talk through how they did it.

As far as I am aware a frame is either interactive or non-interactive based on whether you have chosen to use the mouse with it or just using it as an overlay display like a hud.