Using a vignette causes black screen

Premiere Pro 22.5.0 (Build 62)

When applying a Lumetri vignette to a clip: moving the vignette "midpoint" slider beyond a certain point (eg, about halfway to the left) causes the source and program monitors to go black. Have to reset the slider adjustment (or remove the vignette), and restart Premiere to resolve the problem. Just updated GPU drivers to latest version; still have the problem.

System specs:

Windows 10 Pro

AMD Ryzen 9 3950X 16-Core 3.5 Ghz Processor 3.49 GHz

64.0 GB Ram

Nvidia GeForce RTX30380 GPU  10GB