Mike has a 4K TV streaming through Netflix. But when he connects his laptop to the network, the streams rarely will load at all. Leo says that sending data through the air via Wi-Fi is fast, but he's putting a ton of data through it. Leo says the more distance he has, the lesser the signal. Interference can cause issues, especially in congested areas. 2.4 Ghz is better for longer distances, but it's crowded. 5GHz likely uncrowded, but it may not travel as far through the walls.
Leo recommends getting a repeater to spread out the signal. Mike should get one made by the same manufacturer as his router. Use 5GHz, since it's a cleaner band. There are several apps that will be able to tell him how congested his Wi-Fi area is:
These apps and programs will also help Mike diagnose issues.