Fixed position override

Hi,
Having some trouble on my website. When i edit an order in woocommerce there is a side menu with options. The problem is that when i scroll it adds an css class (.wppb-fixed-position) that changes the position to fixed using this css code:
@media screen and (min-width: 851px)
.wppb-fixed-position {
position: fixed !important;
top: 50px;
z-index: 1;
}
Have tried overriding it but with no avail. Also tried removing the css file completly but it still adds that class. Didn’t find any settings for this either. Is this a bug? How do i fix this?