Why the results of the Viking voyages and the discovery of Greenland and the Vinland

Why the results of the Viking voyages and the discovery of Greenland and the Vinland country were for a long time unknown to European scientists.

The reason that the discovery of America is usually attributed to the expedition of Columbus, and not the Vikings who visited this region in the 10th century, is the fact that for a long time Europeans were not familiar with their historical descriptions and sagas.
The Icelanders used the area for trade and exchange with the indigenous population, without informing the European Community.
In addition, until the early 60s of the 20th century, such questions did not arise among scientists.
Only with the conduct of archaeological excavations on the island of Newfoundland did it become clear that this territory was first visited by the peoples of Europe long before the onset of the period of the great geographical discoveries.