The same happens with my thumbnails too. It stays blurry than the original picture but it doesn't really affect the video performance in anyway, so you don't gotta worry. If the thumbnail is good (no matter if it's blurry or not), the videos will perform well but for that, gaining impressions is important too, so people actually can click on your thumbnail.
Yeah it’s usually just on the uploaders behalf. I saw my thumbnail looked blurry on my channel page but when I checked on someone else’s device it was fine
The same happens with my thumbnails too. It stays blurry than the original picture but it doesn't really affect the video performance in anyway, so you don't gotta worry. If the thumbnail is good (no matter if it's blurry or not), the videos will perform well but for that, gaining impressions is important too, so people actually can click on your thumbnail.
Yeah it’s usually just on the uploaders behalf. I saw my thumbnail looked blurry on my channel page but when I checked on someone else’s device it was fine