I don’t know about the Chinese... but we have Viking settlements that anyone can go visit in Canada (L’Anse aux Meadows)that predate Columbus by more than four centuries...
Yep, and that’s just the one that’s (mostly) undisputed. Hard to believe but true, I’ve got an old book around (circa 1900) that begins with the Viking (re)discovery of America. :’) There was a martinet at the Smithsonian who spent most of his career smearing anyone who said there was any crossing before Columbus. Some people think he was just practicing rigorous scholarship, but he was merely a demagogue.