Open the settings menu on your device, tap on “Apps”, and select YouTube. The next step is to choose “Storage”, which will bring up two options: Clear data and Clear cache. Clear the cache first and check if YouTube now works as it should. If it doesn’t, go back and clear data as well to see if that solves the problem.
For More Information Please Refer: https://www.androidauthority.com/youtube-not-working-811174/