Screensaver stuck on "Flurry" - cannot change on Macbook Pro 2017 running BigSur

[guiobus]

I am stuck with "flurry" and cannot select another screensaver. I have tried deleting the screensaver preference lists in the library, to no avail. Please help. It is really frustrating to not being able to change! I can see the preview of "drift" for instance but if I click on "preview"< I always get "flurry" full screen.

 

[appltech]

Try resetting NVRAM.

Shut down your Mac, then turn it on and immediately press and hold these four keys together:
Option, Command, P and R.
You can release the keys after about 20 seconds, during which time your Mac may appear to restart.

• On Mac computers that play a startup sound, you can release the keys after the second startup sound.
• On Mac computers that have the Apple T2 Security Chip, you can release the keys after the Apple logo appears and disappears for the second time.

When your Mac finishes starting up, you may want to open System Preferences and adjust any settings that have been reset, such as sound volume, display resolution, startup disk selection or time zone.