I don't have the NDI plugin installed. I've unplugged all video cameras. Nothing is currently streaming. So I thought possibly, there is a plugin installed that is causing the grayed-out video settings issue. It turns out I have installed the virtual camera plugin. To deactivate the plugin, pull down from "Tools" to "VirtualCam" and press the "Stop" button. Close the dialog box with the "X" at the top. Don't press "Start".
Now, I can go to settings and edit my video settings.
It's possible a similar plugin in your "Tools" menu is causing the same issue. It may be a case of just finding the offending plugin and turning it off for a moment.
I hope this helps someone in the future.