“Frozen view count
YouTube video views reflect how many times a video has been watched and can be an important measure of a video’s overall popularity.
On some videos, the view count might seem frozen or not show all the views that you expect. Video views are algorithmically validated to maintain fair and positive experiences for content creators, advertisers, and users. To verify that views are real and accurate, YouTube may temporarily slow down, freeze, or adjust the view count, as well as discard low-quality playbacks.
How views are counted
We want to make sure that videos are being viewed by actual humans and not computer programs. During the first couple of hours after a video has been published, we’ll only show views that our systems believe to be valid.”