Th seller may have two identical items, and once one sold, to you, they put the other up for auction, so as not to upset eBay's duplication rules.
I wouldn't worry unduly now, but await your item's last estimated date for delivery.
If a reasonable time passes this , and you do not receive your item, just open a case for item not received, and escalate on day 4, if not refunded beforehand.
@clif_2280
