Six groups of people from Cuba arrived in the Florida Keys over the weekend and Monday, according to the U.S. Border Patrol. In all, 58 people from Cuba arrived up and down the island chain in rustic vessels, said Adam Hoffner, division chief of U.S. Customs and Border Protection’s Miami operations. Around 5 a.m. Monday, 15 people came ashore at the Southernmost Point landmark buoy in Key West aboard a homemade boat, Hoffner said. They told agents they left the Artemisa region of Cuba two days before. Sunday brought four separate arrivals — 10 people on Sombrero Beach in the Middle Keys city o…