Ciao asessa,
Does AS run in real time mode? Does the wx file generated continuously in the shared wx folder? Have you config the NDs link to the shared wx folder? (can be check the EIS\ND.ini file if having the correct path WXRadarPath=\\a320p3d\wxr)
And try to park the aircraft at the place where having the bad weather to check.? If the map inside Active sky has CB then you will have those CBs in Nav Display too.