Are you going by what it says in your My eBay: Purchase History or are you going by what it shows on your card's website/app? If the latter check the "status" of each payment--you will likely find the earlier line item is "Pending" which means it was the pre-authorization you gave when you made the original offer (it will expire in a couple of days) and the "slightly less" one was for the counteroffer you accepted (question: Did you have to checkout to accept it? eBay has started requiring immediate payment, i.e. checkout, in order to accept a counteroffer in at least some cases.)
ETA: And a buyer cannot turn off or opt out of "automatic payment." If you mean as a buyer, you don't. That would defeat the purpose of the program (which is NOT to make checkout "smoother" or whatever else the PR types are trying to spin it as this week).
eBay had been "experimenting" with requiring pre-authorization of payment for Best Offers for over a year and a half (started prior to Halloween 2021), adding more and more users into the test group required to do so (sellers can opt their listings out of it; buyers cannot opt out once they are assigned). Too many users were making offers and then not paying when it was accepted, and too many of those were scammers who would try to get the seller to text or email them to get their number/email address to send fake payment messages to.
They made it permanent in Fall 2023 and all buyers are now required to pre-authorize payment for Best Offers they make on listings for sellers who have not opted out of the program. They started trying it out on auction bids (with a smaller group of buyers that is growing) in Spring or early Summer 2023 but that seems to have been ended without being made permanent and universal. They also started experimenting with requiring immediate payment for accepting offers from sellers this Spring.
You can try to find a seller who opted his/her listings out of the pre-authorization requirement. Unless s/he says s/he has in the item description you'd need to actually try to make an offer and if it goes through without you having to add or confirm (with links to edit) your shipping address and payment method then s/he has opted out.
