this one? https://www.wincustomize.com/skins.aspx?skinid=515&libid=22
window stops at both top and bottom bar for me
switch to builder mode then right click the tray icon and configure or run the helper and choose configure
under the desktop tab choose workarea, the option to reduce should show as checked with the top set at 83 and bottom set at 80
the theme was designed to hide your regular taskbar and replace it with the bottom bar - both bars being 'set' to reserve space so your window won't go over it
if you want your window maxed over the whole thing uncheck the reduce option - switch back to client and save your desktop so it will remember