Hello. In my case, the problem had to do with the button getting focus. While The resulting behavior is still strange to me, it is fixed by unchecking the ‘Is Focusable’ checkbox in the details for the button. If this does not fix the issue, please explain in detail the setup you’re using and I may be able to help.
For example, Are you using the buttons *OnClicked * function or OnMouseButtonDown? using the OnMouseButtonDown overridable function with a button, left clicks will be overridden by the buttons OnClicked function, while right mouse buttons will use the *OnMouseButtonDown *function.