Based on the feed back from many different YouTubers now @TeamYouTube!
YouTube is infact broken. Notifications are not working. And people are getting recommended videos that are two months to two years old.
Youtubers are experiencing a 20% to 30% loss in views.
Maybe nothing wrong in the original coding etc etc. But have you guys ever thought that every computer is different with different settings with different webbreaders? I don't know what you exactuly looked in to, but it might be time to expand the search for the errors.