The problem you have described looks like the infamous Internet Explorer "Guillotine" bug, which they promised to fix, but obviously forgot. In a few words - an absolutely positioned element in a parent with scrollable overflow causes the element to remain fixed, instead of scroll along with the parent.
However, there is a fix. Simply add position: relative to your parent div.
Unfortunately, this is a browaer behavior we cannot control, so the only thing we can suggest is to use the above hack.
the Telerik team
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