An outdated FireStick OS may also cause buffering. It is rare but quite possible. Usually, your FireStick will update itself automatically whenever a new OS version is available. However, sometimes, it may not.
Therefore, if you are facing a buffering issue, it is important to ensure that your FireStick OS is up to date. Here are the steps to check for and install OS updates:
1. Go to FireStick Settings.
2. Open My Fire TV.
5. Wait for a few seconds. This screen will let you know whether any updates are needed or if your device is already up to date.