Media paths are not updating to new number prefix

I have a modular page which haven't been number prefixed. After setting all modular pages to number prefixes and changing the order of the modular pages the media paths are not updating to the new prefix number. I am not sure whether is a grav core or grav admin bug. I have put this issue in the admin repo because of have changed the settings in the admin (grav 1.5.0 and grav-admin 1.8.8).