I sent a buyer an offer yesterday which they countered and I accepted.

I didn't get the usual sale notification and noticed that it went back to them like a counter offer for the same price and the item is still live as they haven't paid.

Is this a change to the offer system so no buyer can have an unpaid buy it now item?  I don't mind it but I am confused by it as I haven't seen any announcement that this will now happen.

As the buyer hasn't paid I am wondering how this acceptance appeared to them at their end. Do ebay tell them I accepted or do they present it as a counter offer? My buyer might think I was being fly here and seems to have pulled out from buying so I am just curious. Thanks