This is a nonissue. I’ll dismiss this as being my fault, only (though I believe it’s been fixed, so you may need to update your plugin). The issue stems from two things:
- The buttons have one click detector which is actually the frame they sit on. Math is used to determine which button is clicked.
- Team Create has a network, so my code expects there to be a top bar screwing things up.
The code which decides whether there’s a header now compares mouse.ViewSizeY with the AbsoluteSize.y of a frame of size UDim2.new(0, 0, 1, 0), instead of the old way of deciding on a case-by-case basis. It remains to be seen whether it will be better. 
If you want to say there’s a bug, it would be that the following code is wrong.
local x, y = textButton.MouseButton1Down:wait();
print("Absolute Coordinates: ", x, y);
print("Relative Coordinates (to textButton): ",
x - textButton.AbsolutePosition.x,
y - textButton.AbsolutePosition.y); --> This is not right, but it should be.
Basically, what I’m saying is that if AbsolutePosition is measured from the bottom of the top bar, so should everything else. And I would happily see my code break again to undo this pain.