Hey @jasonbarry Thanks for bringing this to our attention. I will start to look into this a little more today

I looked into this a little bit, and I think I know the cause of the issue (although not the solution).

Overlay is listening for onClick events from the Box component that makes up the overlay and its children.

Of course, these onClick events will fire for any click inside the overlay (including inside the children, e.g. Dialog/SideSheet) which is undesirable. So the handleBackdropClick handler checks that the currentTarget (the element where the handler is registered) is the same as the target (the element that fired the onClick event)

This ensures that clicks inside of the children do not close the overlay. However, there is a problem with this approach: onClick is only fired for mousedown+mouseup where both events fire in the same element. But since Box encompasses both the backdrop and the children (e.g. SideSheet/Dialog), any click inside any part of the overlay will result in an onClick event.

So I think what we're seeing is that some browsers (Chrome) use the mouseup element as the target, thus defeating the check target === currentTarget in cases where the mouseup is on the backdrop, even if the mousedown is in the children.