Using the current version of ‘autohide_sidebar.css’ the open sidebar now overlays and obscures part of the page Content window.
This has always been the intended behavior of that style. If you experienced something else previously then either you weren't using that style, you had some modification to it, or it didn't work correctly for some unknown reason.
But if you do want that kind of behavior then you can get it with something like this:
#sidebar-box{
--uc-sidebar-width: 40px;
--uc-sidebar-hover-width: 200px;
--uc-autohide-transition-duration: 115ms;
--uc-autohide-sidebar-delay: 600ms;
--uc-autohide-transition-type: linear;
min-width: var(--uc-sidebar-width) !important;
width: var(--uc-sidebar-width) !important;
transition: min-width var(--uc-autohide-transition-duration) var(--uc-autohide-transition-type) var(--uc-autohide-sidebar-delay);
}
#sidebar-box:hover{
min-width: var(--uc-sidebar-hover-width) !important;
transition-delay: 0ms;
}