Brooklyn issue (10.0.4) - theme editor does not save changes

I tried that already actually. I set every border to 0 for #d8dde6. But the light border still shows up on my field editor in both read only and editor mode. Is it hard coded somewhere in the product?

section header: Border (Bottom) checked 0 border-bottom
section: nothing is checked
field item: Border (Bottom) checked 0 border-bottom
field input: border checked 0 border-bottom #a5a5a5
border required checked 0 border-bottom #d8dde6

It appears that the above field editor styles apply to
.nx-field input, .nx-field textarea, .nx-field .flex-text-wrap pre, .nx-field .nx-richtext-input

It does not relate to nx-basicfieldeditor-item.

There is a very light line below the editable field that I want to remove. It only appears on the actual page, not in the theme editor. From the web console, I can see it’s from nx-basicfieldeditor-item, which the theme editor does not update.