Trc4
The MobileTab CSS might not be related to this . If you can provide the site link, I can take a look.
.MobileTab {
position: fixed;
bottom: 0;
left: 0;
width: 100%;
height: calc(var(--mobile-tab-height) + env(safe-area-inset-bottom, 0));
background: var(--mobile-tab-bg);
box-shadow: var(--mobile-tab-shadow);
z-index: var(--mobile-tab-zindex);
isolation: isolate;
}