QTabBar strange line doesn't disappear - qt

Question

I have created this interface:
My Question is: HOW TO GET RID OF THAT OBSOLETE LINE using my stylesheet.
The black frame (objectname= mainTabBarWidget(QWidget)) is laid out vertically. It has a Fixed height (38px) and contains these elements from left to right: QToolButton, QTabBar, QToolButton, and another QToolButton.
Its stylesheet is the following:
QWidget#mainTabBarWidget {
border-bottom: 1px solid black;
background-color: rgb(107, 102, 102);
}
The "+" QToolButton creates a new Tab whenever its clicked. The QTabBar (called tabBar) has this stylesheet:
QTabBar#tabBar{
left: 10px; /* move to the right by 5px */
border-bottom: none;
}
QTabBar::tab {
background-color: rgb(194, 180, 180);
border-top: 2px solid rgb(107, 102, 102);
border-left: 2px solid rgb(107, 102, 102);
border-right: 2px solid rgb(107, 102, 102);
border-bottom: none;
border-top-left-radius: 10px;
border-top-right-radius: 10px;
border-bottom-left-radius: -8px;
border-bottom-right-radius: -8px;
min-width: 100px;
max-width: 100px;
height: 35px;
padding: 2px;
}
QTabBar::tab:hover {
background-color: rgb(216, 209, 209);
}
QTabBar::tab:selected {
background-color: rgb(243, 231, 231);
border-color: rgb(0, 0, 0);
}
QTabBar::scroller { /* the width of the scroll buttons */
border: none;
width: 20px;
background-color: rgba(0,0,0,55);
}
QTabBar::tear {
border: none;
background-color: rgba(222,221,15, 45);
width: 0px;
}
QTabBar::tab:disabled {
border: none;
}
P.S.1. When 3 or 4 tabs are added, the line disappears too.
P.S.2. I tried setting the tab width to 120px and the line disappeared, but when I add other tabs and the scroll buttons show up, this line re-appears.

Answer 1

I had a similar problem, but it was solved below.
http://doc.qt.io/qt-5/qtabbar.html#drawBase-prop
QTabBar::setDrawBase(false);