Latest FF missing themes Customizations Tabs?

[StormJumper]

I have one computer even after copy the latest CSS it still stays the same default from Mozilla install. I check about:profiles and about:config and copied the CSS and still not showing. But when I check one that has this customization I see three boxes on the Customization lower screen:

A Check Box (empty) : Toolbars : Themes : Density

A Check Box (empty) : Toolbars : Density
This one is missing : Themes
The other computer isn't showing this I tried to back to default but that "Themes" still doesn't show up? So did something during my standalone FF install this option went missing? I saw this when I went from 89 to 9x version. All of my FF updates were just upgrade to the previous version so no complete removal of the browser. Three did keep the customization but one for some reason didn't. Do I need to remove FF from this computer complete and reinstall it? Instead of the theme box option it says "mange Themes" only nothing of options to choose as previously. Do I need to uninstall and wipe clean Mozilla folder to fix this? So I am reverting back to previous drive images to figure what is going on with FF and why it's just this one computer doing this.

[StormJumper]

I reverted back on images but past 85 it messes up the "Theme" option box on the computer that for some reason losses when I upgrade FF on that computer.