1 or 100,000 the point is people who made the crossing did not get a popup saying "achievement unlocked: new continent!" And then run around telling everyone about it.

Yes, European mapmakers did not known about such crossings, but being a very remote area in 1400's they probably never asked. And from an oral history perspective it would not be anything unusual because a 50 mile ocean crossing is just a regular thing to sea going populations.

Also, DNA evidence is going to be sketchy because it's really hard to say if someone migrated 400 years ago vs 600 years ago.

PS: I am not saying this 100% happened, but it seems very likely.

"1 or 100,000 the point is people who made the crossing did not get a popup saying 'achievement unlocked: new continent!'"

Yes, that is the point that I made above. The people had no idea.