eBay

Here is the answer for you.https://www.ebay.com/help/policies/payment-policies/offering-buy-sell-outside-ebay-policy?id=4272&st=12&pos=1&query=Offering%20to%20buy%20or%20sell%20outside%20of%20eBay%20policy&intent=buy%20o&docId=HELP1286

Actually you can ask seller to cancel that order for you, but that's not the thing I would recommend you to do. In this situation, and you also wanna buy these 2 items, then you just go to checkout and pay. Done!

Thanks for your helpful post. I think I may face with this problem in the near future.

If we add all the item specifics as required, is this issue disappeared?