Inconsisten margins in the preferences
On the preferences sections, the margins of the panels are quite inconsistent, presenting different width black like between them.
OS: Arch Linux Gnome Terminal: 3.40.1 Wayland Session
In this picture, you can see that the left panel has a bigger top-margin than the right panel
When going into the profile section, panels have a more consisten margin between them, but has a different margin compared to the previous screen (See the black line blow the window title bar on this screenshot compared to the previous one) though I'm not sure if having such a big "black line" between them is the correct thing.