Your 4K streaming stick keeps buffering, and it probably isn't your Wi-Fi

A streaming stick that buffers, stutters, or reboots itself halfway through an episode is one of the more maddening things a living room can throw at you, not least because the obvious suspect is rarely the guilty one. The reflex is to blame the Wi-Fi, restart the router, and grumble about the broadband, and sometimes that's fair.

Source : https://www.pocket-lint.com/4k-streaming-stick-buffering-power/