GUI mouse just works once

I downloaded the UI Curved from UNity Assets. When I Run the scene in Unity everything is working fine, then I stopped it and play again and is is not working anymore, I can see the scene but when I drag the mouse over a button it doesn’t highlight or press. I have to restart Unity and everything start working again. Why is it working just the first time?

when i put it in the phone works correctly, then I know something is wrong in Unity in my computer.

okay, it is not happening just with the curved UI Assests. I started a new project, and happens the same. It just let me put the mouse over the button and it goes highlighted, the second time I run the project It does not highlight.

Im sorry for my english, i’m learning.

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