10.4.8 Viewer background preference does not work

I usually have the viewer background as black, but sometimes when dealing with files with transparency, or when placing 4:3 images in a 16:9 frame it is useful to set it to checkerboard or white.

Since updating to 10.4.8, the viewer background always stays as black, regardless of the setting in Preferences->Playback.

I deleted preferences, of course, but it does not fix it.

Before I use feedback to report this, I'd like to know if others are seeing the same problem.

TIA