Are you accessing YouTube using the YouTube App - or via Safari or other web-browser? If you are using the YouTube App you may need to seek assistance from the App Developer - Google.
How to contact an app developer - Apple Support
https://support.google.com/youtube/?hl=en-GB#topic=9257498
Otherwise, a forced-restart of your iPad may be helpful - as doing so will often resolve an isolated software issue:
- On an iPad with a Home button: Press and hold the top button and the Home button at the same time. When the Apple logo appears, release both buttons.
- On other iPad models: Press and quickly release the volume up button, press and quickly release the volume down button, then press and hold the top button. When the Apple logo appears, release the button.
