Hi, blender's developer, I recently encountered an issue with Asset Browser. I can't find any task descripe this, so I report here.
Asset Browser show assets thumbnails immediately when I mark asset for some data-block first time. It work fine at this time. But when I close file and reopen it, Asset Browser doesn't show thumbnails of current file's assets.
However, It work fine when browse this file's asset at other file.
Blender 2.92.0 asset-browser branch - ee5ecb48f441
This appear on both win10 and macOS 11.2.2 .