@TeamYouTube Custom Thumbnails won't show while signed into a specific YouTube account, but they show while signed out or signed into any other account. Also, this happens on all platforms. And instead, it shows a random screenshot from the video.
You can add location information to your Tweets, such as your city or precise location, from the web and via third-party applications. You always have the option to delete your Tweet location history. Learn more
@TeamYouTube Custom Thumbnails won't show while signed into a specific YouTube account, but they show while signed out or signed into any other account. Also, this happens on all platforms. And instead, it shows a random screenshot from the video.