Lumetri/Adjustment Layer - White Screen Error

[NHEDIT-16]

When I add a lumetri effect and make any adjustment my playback turns to white. It's happened before and this specific time it went to white when I tried to add some vignette to my image. Didn't change any other attributes inside Lumetri. 

Seems like it's an error with Lumetri? Rather an inconvenient error because I can't make any changes without the image turning to complete white. 

Tried nesting to get around it but didn't have any luck. 

Working on a new 2021 m1 Mac mini. 

[RobShultz]

Are you rendering after applying the effect?

If there is a red line at the top of the timeline just press return to see if that helps.

[Michael Grenadier]

what are your source properties and your sequence settings?  Any chance any of your sources are from a smartphone or a screen recording?  If so, the problem may be sources with variable frame rate.  Here's how to diagnose and resolve the issue.

use mediainfo to determine whether your source is variable or constant frame rate
https://mediaarea.net/en/MediaInfo/Download
if it's variable use handbrake to convert to constant frame rate setting the quality slider in the video panel to maximum
https://handbrake.fr
and here's a tutorial on how to use handbrake
https://www.youtube.com/watch?time_continue=34&v=xlvxgVREX-Y