https://www.gamespot.com/articles/destiny-2-nightfall-strike-guide-the-arms-dealer-m/1100-6454516/

Another weekly reset has arrived for Destiny 2, which means it's time for a new Nightfall Strike... except it doesn't. The Flashpoint has moved to the EDZ, but despite the reset, players still have access to the same Nightfall as last week: The Arms Dealer. It features the same exact Challenges but different Modifiers, which is unusual. We do know that a new Destiny 2 update is slated to arrive this week, and it's possible the Nightfall will change following that. We'll update this story if that proves to be the case, but for now we'll look at the Nightfall version of The Arms Dealer. [Update: It's Monday, meaning there's less than a day left to complete this week's Nightfall before the weekly reset.]