@YouTube My thumbnails are generating in random parts of my videos to my viewers. I spend almost an hour creating my thumbnails. Lots of other creators are having this issue too... please please do what you can and fix this problem.
Note that 99.7% of viewers still see your custom thumbnails and it shouldn’t affect your channel in any significant way (watch time, views, etc). We want to improve auto-generated thumbnails for the many creators that use them. Details here: https://goo.gl/A7oDmr