Column Menu has a list of columns available in the Grid, When we uncheck selected Column from list (that is hiding from the list). That time Column has to be close. As of now, hiding column from the list using Column Menu makes Column Menu to jump to top corner of the browser.
I am unable to reproduce this oddity on this demo following the steps you described: http://demos.kendoui.com/web/grid/column-menu.html What you see is unexpected behavior in your app, most likely caused by relative or fixed positioning via css. To address it, please file a formal support query using our forums or support system on kendoui.com