That's odd. Lets make sure that you're running the most updated OS on your device. Also, updating the app or reinstalling it often fixes most issues. Let us know if that works.
Thanks for the report. Please send a feedback report directly from YouTube with these steps for us to work on it: https://goo.gl/WdI0BK . While every individual report may not get a direct response, we do review everything and use the details to investigate and fix issues.