Windows client no longer shows thumbnails, even for items made available locally

When I enable virtual files for a folder, I get no thumbnails even if the file’s downloaded. Needless to say, this is pretty inconvenient for photos. is this a bug, or am I missing something? Previous versions of the client definitely didn’t do this, I remember being able to download and view thumbnails.

For reference, here’s a screenshot of the same folder with the client reverted to 3.5.2, working as expected.

You created a bug report already: