I can’t seem to find any verse in the Bible at all saying that Ham was black, let alone the first black man as you claim. Even if you accept that claim, he was long dead before Lehi left Jerusalem and nothing in the verse is mutually exclusive of what the Bible says of Ham so there is no contradiction.
You can't see the nose on your own face without a mirror.
"Ham," "chamam", means "black," or "to be black." Same with his first son Cush. (Land of Cush = Ethiopia.)
"nothing in the verse is mutually exclusive"
Since when did God ever appoint a sign for a curse which existed elsewhere?
You want a real sign? Ask any mother about the pain of childbirth.