You came to the right place!
Have you tried changing your screensaver/theme to a different option, rebooting your device from the Settings menu, then applying that theme/screensaver once more?
If that still isn't doing the trick, please send me a PM with your Roku account email address and the serial number of your device and I'll help take a closer look.
Starting about three months ago the scrolling city background on the Movie Magic screensaver stopped showing up. Instead, I get a bouncing "Roku" in white on a black screen.
Not sure how to resolve -- I don't see any options or configuration and I can't seem to remove the screensaver to try reinstalling it. Can anyone help?
EDIT: Screensaver version is 3.0.28, updated 14 Nov 2019. Roku Streaming Stick 3800X, software 9.2.0