Preview thumbnail images fail/not generated for Site Studio Components

I have the same issue and I manage to solve it by changing one line of code in "src/Plugin/media/Source/Asset.php" - line 283.

return $this->getRemoteThumbnailUri($external_id) ?: $asset['thumbnails']['600px']['url'];

to

return $asset['thumbnails']['600px']['url'] ?: $this->getRemoteThumbnailUri($external_id);

For me $asset['thumbnails']['600px']['url'] - has right preview path and $this->getRemoteThumbnailUri($external_id); generates wrong one.

I was not digging further into it, but I hope it will help someone to fix the source of issue.

Added a patch to enforce widget_table view mode as a quick fix to this missing thumbnails issue in a default D10 site.

Hello @ibullock, Could you please outline the exact steps to reproduce the issue?