One slow device can cripple your entire Wi-Fi network while using barely any data

When your Wi-Fi network feels sluggish, your instinct is probably to blame the ISP, router, or an errant device hogging all the bandwidth in the background. Maybe you forgot about a huge download or a 4K uncompressed movie streaming to your TV, but more often than not, the culprit is a device that isn't using any data at all. It's simply too old or slow to play well with your Wi-Fi.