also define the standard property 'border-radius' for compatibility css(vendor prefix)

/* Keyword values */
transition-property: none;
transition-property: all;

/* <custom-ident> values */
transition-property: test_05;
transition-property: -specific;
transition-property: sliding-vertically;

/* Multiple values */
transition-property: test1, animation4;
transition-property: all, height, color;
transition-property: all, -moz-specific, sliding;

/* Global values */
transition-property: inherit;
transition-property: initial;
transition-property: unset;

.scrollbar-black::-webkit-scrollbar-thumb {
    border-radius: 10px;
    -webkit-box-shadow: inset 0 0 6px rgba(0, 0, 0, 0.1);
            box-shadow: inset 0 0 6px rgba(0, 0, 0, 0.1); // <- Add this to fix.    
    background-color: #000;
}

Also define the standard property 'filter' for compatibilitycss(vendorPrefix)