The notice that another tab holds the chats is a card in the middle of the blurred chat panel, as Jump to's layer blurs it, rather than a line of unstyled text, and so is the one for a store that failed to open. The page behind can't be reached by pointer or keyboard, the card's button takes the keyboard, and the card stays up with its button busy while a retry waits. BusyBanner becomes StoreUnavailable, which wraps the page, and the error page's round icon mark becomes IconMark, shared by both.