Unfortunately I don't have steps to reproduce but it happens relatively often that Fenix loses the thumbnail of GitHub. Fenix only shows a white area, but the thumbnails of other tabs are still there.
UNITO-UNDERSCORE!20200614-162937!
Fenix doesn't lose a thumbnail. But if it happens for whatever reason I would expect that all tabs are affected and not only GitHub.
It's not only github but other sites are affected too. This happens particularly in mobile data.

It loses thumbnails randomly from any site as far as I can tell - it doesn't matter what the domain is.
Not only thumbnail ,in the top sites too the favicon is lost sometime...sometime the icon shows sometime a letter only.
I was able to reproduce this issue on today's Nightly build (6/25) with HTC 10 (Android 8):

Similar with #11733 ?
Noticed that after you put Fenix in background and resume the screenshot is lost
With the latest AC version, this should be fixed now!
Hi, verified as fixed on the latest Nightly Build 200826 using the following devices:
• Google Pixel 3a (Android 10)
• Huawei Mate 20 Lite (Android 10)
• OnePlus A3 (Android 6.0.1)
► Video
