Editor External Border

[xcrap]

I keep switching from a Zed theme for my own blurred translucid theme override, today when i returned I saw the border, this was not here some days/weeks ago. Anybody knows what is this specific property, uhhh i want to remove it right now :) I think i remember reading some border stuff on recent releases but I don't know if it's related and I can't find it.

[xcrap]

Anybody? o.O