We're here to help. Does this happen across devices? Also, try uninstalling & reinstalling the app updates after restarting the device to see if that makes a difference. Keep us posted.
That's odd! Please send a feedback report directly from YouTube with these steps: 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. Thanks.