Buyers are suddenly able to purchase items without immediate payment?

I had a sale recently for a rather pricy $110 item, however what is strange is the buyer purchased it without paying. Now this is normal for cases where an offer is accepted or an auction is won, as they buyer doesn't have to pay right away, but there was no offer sent and the item was purchased at asking price. It has been "awaiting payment" for the last 3 days.

I thought maybe this was a glitch/fluke, but a few hours ago I had a $25 item sell without immediate payment either! Now that item, which also had no sent/accepted offers, is also sitting as "awaiting payment".

I've been selling 3 years and hadn't ever seen this happen, so for it to happen twice in such a short time makes me think a change on eBay is to blame. Both these purchases were from international buyers, which could have something to do with it. I have messaged both buyers asking them nicely how they purchased the item without immediate payment, but neither of them have responded as of yet.

Has anyone else experienced this? Is there some setting I can toggle? Is this a known issue?

I don't like the idea that anyone can put my listing into a 6 day limbo at will, which is the time before I can cancel the sale due to lack of payment.