it's the YouTube app I've had the same issue to make sure your running the 17.01.35 version uninstall the update. This issue occurs after updating the latest YouTube app version(17.14+).
In the meantime, as a workaround, Please press and hold the YouTube app icon > (i) > Three dots (Top right) > Uninstall Updates. Yes even if it says uninstall the entire app it won't delete the whole app as this is build pre-installed app. I'm happy that solution helped you 😊. Just keep up to date with YouTube see if they fix the issue and features doesn't matter you rather watch something on YouTube then having to face issues 😊.