@Whatintheworld1 Hi. I've stumbled across this thread while having essentially the same problem. (And, while I won't linger on this for too long, I'm also getting a similar impression about leocg... I'm wondering if the reading comprehension issues might [partially] be due to a language barrier, perhaps? "I may have difficult in understand bad written posts. So, what exactly did I misunderstood?" certainly isn't proper/correct English grammar...)
Did you ever find a solution? Ironically, I'm dealing with the same thing, just,,, from the reverse perspective: Opera GX has things showing up in a 24-hour format, but literally everything (i.e. my system settings, etc.) is set to 12-hour format on my end.
It's not website-specific, either : I even checked the exact same site + page, using a different browser. It was normal (i.e. matched my system settings) in the other browser.