Thumbnail issue - Fixed format epub

Hi team,

The thumbnails are displaying properly for the reflowable format epub in the ADE library. However, the fixed format epub's thumbnails are not showing properly. If the viewport is exceeds 1200 width, the thumbnails shows the blank image. less than 1200 width, it shows the cover image partially. I know, ADE fetch the thumbnail from the first page of title. For fixed format, it seems to be bug. Someone check and advise as soon as possible.

Thanks in advance,

Rajesh Kumar