Simbrief assigning too high Cruiz Alt

Hello, I currently fly in Norway quite a lot and SimBrief has been setting me cruising altitudes which are too high for my Vnav Decent profile (Flown in the PMDG 738). I was wondering if there was any reason to why this may happen or if there is anything i can do to allow my TOC and TOD not to overlap and get a “Unable Crz” on my FMC.