Updated
Quick fix
Restart the TV or streaming device and the router, test the internet speed on the TV itself, and move the router closer or use a wired connection if Wi-Fi is weak. Lowering the video quality setting helps on slow connections.
Step by step
Restart the TV or streaming device
Unplug it for 30 seconds. Smart TVs often only sleep when you press the power button.
Check other apps
If every streaming app buffers, it’s the connection. If only one does, update that app or check whether the service is having problems.
Test speed on the TV
Many TVs and streaming devices have a network test in their settings. Compare the result to what the streaming service recommends on its help page.
Improve the connection
Use an Ethernet cable if the TV has a port, move the router or add a mesh unit nearby. See Wi-Fi dead zones.
Reduce competition
Big downloads, game updates and backups on other devices can cause buffering.
Update
Install TV or streaming device software updates and update the streaming apps.