how to get weapon mods in lightfall

[errant flame]

I have been trying to get the boss spec mod but banshee no longer sells them so how do you get it now?

[knotty sky]

all mods except for adept mods are unlocked if im right. issue is that if you check if you have it via collections, itll say youre missing it, but if you go to a gun and try to slot in a mod, itll be there