Hi @kafkanarchy84,
Firstly let me apologise for the thumbnails being temperamental, I know its very frustrating.
We are aware of the issue and our developers are working on a fix - I can assure you of that.
In the meantime, we are advising users to edit their steemit posts with a new thumbnail. I know it's not ideal, but it is a small workaround.
We are always in the DLive discord if you would like to discuss anything further, and my DM's are always open there :)
Link to our Discord: https://discord.gg/vnXQBsM
Kindest Regards
TidyLIVE
DLive Community Team
Thank you. Really appreciate this.