Hello.
I found a small CSS bug, on specific resolution @media (min-width: 768px) and (max-width: 991.98px) there is small horizontal line below/after side navigation:

    border-bottom: 1px solid var(--control-bg);

It looks like:

To suppress it I suggest add a new CSS rule:

.sideNav:after {
    border-bottom: unset !important;
}