Until a few days ago, on the basis of many similar issues reported here over several years, I would have warned you that eBay goes entirely by the tracking record. If it's tracked as delivered, eBay does not hold the seller responsible if it's stolen after delivery (which is becmng a commonoccurrence). So no refund.
However, last week (I think ) a buyer reported exactly the same experience, whereupon several responders replied with the advice above.
The buyer contacted eBay customer support, who apparently promised that they would be refunded - leading the buyer to post here again to say we didn't know what we were talking about! Which may of course be true, if eBay has changed this policy recently.
This could be due to simple delivery, but eBay doesn't tell us about changes in policy. To add to the difficulty, the new "easy reading for online use" version of its money back guarantee omits many previously of the stated terms and conditions.
So do please post here to let us know the outcome . Also, think about contacting cstomer support in person before opening a money back guarantee case - eBay staff may perhaps be more customer-friendly than eBay's awful, so-called AI which seems to dominate today.