I have had this happen a few times, and a few times when there has been the lipbalm, where it gives me an error that says "Oh No! We have no record of this floating item". It happens way too often for my liking, and right after I clicked on the item.

I've had this happen to me in the case when I navigate away from a page or in multiple tabs. Unfortunately, after claiming one item (lets say in another tab), the one in this tab no longer exists. It gets confusing, but I've gotten it before, so that may be why it is happening to you. If this is not the case, that you are using multiple tabs, then the staff will probably look into it. It may also be an issue with lag.