A booking is showing up on my Google calendar twice. Once with a [B] in front of it and once with a [U]. Why?

If you are showing a U and a B that indicates there are two bookings, one booked B, and 1 pending U. I've seen this happen occasionally right after I modify a booking and then confirm as does the client. But the pending booking is a ghost, but check your pending folder to see if the ghost appears. I've also seen this clear up in a day or two.