Evidence shows that Scandinavian seafarers visited the Azores a considerable time before the Portuguese.

If you live in the Middle Ages and are surrounded by the cold and harsh landscapes of Scandinavia, exploring other places was probably considered a good idea. Especially if there are the Azores on Earth and relatively nearby - an archipelago of nine attractive islands in the middle of the Atlantic Ocean, about 1400 km (860 miles) from the coast of Portugal.

A recent study* suggests that Viking travellers reached the Azores several centuries before Portuguese seafarers. Moreover, when the Portuguese arrived on the islands, they did not find traces of the Vikings, but the aforementioned study has found clear evidence: the Vikings were the first on the islands.
* https://www.pnas.org/content/118/41/e2108236118 (Climate change facilitated the early colonization of the Azores Archipelago during medieval times)