iPad requires the UIPopoverPresentationController be anchored to something in the view. It's not and so an exception is being thrown.
<rdar://problem/102067010>
Pull request: https://github.com/WebKit/WebKit/pull/6234
Committed 256436@main (1713bed5d0c7): <https://commits.webkit.org/256436@main> Reviewed commits have been landed. Closing PR #6234 and removing active labels.