Apple TV performance issues can take the form
Reduced video quality
Lower frame rate
Slow motion video
Long buffering times
Please see the below steps to improve the performance on your Apple TV to get it running like new again.
Restart your Apple TV:
Restart your device by selecting Settings > System > Restart.
Alternately, you can force restart your Apple TV by simultaneously holding the Home and Menu buttons on your remote for about 10 seconds, until a white light on the Apple TV starts flashing. Then, release the buttons on the remote to restart the device. You can also unplug your Apple TV, wait 30 seconds to a minute, and plug it back in.
Connect to the Closest Base Station:
If your Apple TV device is connected to WiFi, and you have multiple base stations in your home, make sure your Apple TV is connected to the one it is located closest to for the fastest streaming. If you have recently rebooted the nearest base station, your Apple TV may have connected to one further away, resulting in weaker signal strength. Rebooting your Apple TV should allow it to reconnect to the nearest base station.
WiFi vs. Hard-wired Connection:
Try disconnecting and reconnecting from your WiFi network by going to Settings > General > Network > WiFi. Select the name of your WiFi network, then Forget Network. Reconnect to the network to see if the streaming speed improves. Try connecting your Apple TV directly to your router or modem via an Ethernet cable to see if this improves streaming speed.
Congested Internet Connection:
If other devices on your WiFi network are running downloads, uploads, updates, or streaming video, this may saturate your internet connection and cause slower streaming.
Reset Your Apple TV’s Settings:
This can sometimes remove corrupt files that may be causing your Apple TV to run slowly.
Go to Settings > General > Reset > Reset All Settings.
Restore Your Apple TV:
If none of the above options improved your Apple TV functioning, you can try Restoring. Please note after restoring you will need to reconnect to your WiFi network, and you will be signed out of apps.
Go to Settings > General > Reset > Restore.
NOTE: Do not unplug your Apple TV while the Restore is in progress.