In modern Vector, the ULS trigger button has a child node which is
a span. When clicks are received on the span, they will result
in positioning relating to the span rather than the button.
The ev.currentTarget should be read outside the asynchronous function
to avoid bubbling.
Bug: T276248
Change-Id: I6e138c88e29b335b8e0bc22cf0aa07c289a5eb74