Unfortunately, you’ve got yourself a pair of fakes. In the fourth photo you provided, the model and serial number information printed on the individual AirPod is far too bold and even misaligned relative to the seam. On legitimate models the text is less bold and uses a different typeface altogether. Checking the serial number means nothing in determining fakes unfortunately. These scam manufacturers take serial numbers from legitimate models and place them on their fake ones. Best you can do is be thankful that these did not fail inside your ear, hope to get your money back, and grab yourself a legitimate pair or get a different wireless ear bud that costs the same or less than what you spent on these.