This has been reported by many YouTuber an issue with YouTube’s Analytics which is showing lower then normal values of view count, watch time and impressions.
Google has confirmed this issue. 
You can check this thread here https://support.google.com/youtube/thread/22343886?hl=en-GB
My youtube watch hours also didn’t increased….
This issue has been resolved and reported by Google team. Check https://support.google.com/youtube/thread/22343886?hl=en-GB