Your router avoids the best 5GHz channels by default, and turning on DFS gave my Wi-Fi room to breathe

When you set up a high-end router in a suburban neighborhood or apartment building, you might find that your 5GHz network is choking on overlapping channels while half the spectrum sits completely dormant. Out of the box, most consumer routers restrict themselves to the lower non-DFS 5GHz channels to avoid regulatory fines or interference with weather radar and military frequencies. By leaving dynamic frequency selection disabled, you are voluntarily fighting for scraps in a crowded four-channel pool. Unlocking DFS channels opens up a massive interference-free superhighway that gives your Wi-Fi network room to breathe.