That's odd, you could try these steps: delete the app > restart your device > reinstall the app. This usually clears things up but let us know if it's still not working.
Sorry for the trouble. We'd recommend sending a feedback report directly from the account experiencing the issue on YouTube: https://goo.gl/WdI0BK . While every individual report may not get a direct response, we do review everything and use the details & fix issues.