Blend-Files Preview Thumbnails with Background Images in March 2019 when Blender 2.8 non-stable was released, there was a feature added which is apparently missing now from the 2.8 stable release.

In the previous release you could see the camera background images in your .blend thumbnail preview.

With 2.8 stable they're all gone. Is there any way to get this feature back?




Thanks!
In the Blender File Browser was able to show previews by clicking on box shown and the clicking on show previews.

My bad, did not notice I was in 2.81. Switched to 2.80 and does not work.
Sorry for incorrect information.
In my present version of 2.81 the settings in preferences don't stick.