Apologies if this may sound like a stupid question that could be answered with a quick Google search, but Google is often wrong about things relating to history. I know of the attempted settlements of Vinland, but I always thought that its discovery was "lost" to Europeans.
Sorry for just a copy&paste from a link post to the similar question thread earlier in this week (it's a kind of very FAQ).
There will always be more to be discussed in detail, but I posted some answers before to similar questions as OP's:
In short, I suppose that the rumor of Vinland itself, an other-worldly island in the ocean, sounded not so promising and it was not so likely to have attracted few attraction from foreigners in the Middle Ages.
The 'a landmass west of Greenland' part also sounds a bit suspicious to me.
As I explained in Why did the Scandinavians forget about the SKraeling (Inuit Peoples) after Viking Contact? Or did people in Iceland and Norway maintain contact with Greenland?, some medieval authors seem to interpret the possible landmass around Greenland either as an extension of either Africa or Eurasia Continent, not necessarily as the third, totally unknown land.
AFAIK there was no positive written evidence prior to the 15th century that medieval Norse people thought three lands west of Greenland, namely Helluland (Baffin Island?), Markland (Labrador), and Vinland/ Vínland, constituted the same group of land or landmass.
(Edited): fixes typos.