(PS4) Rank 5 Life craft unobtainable?

Grabbed the crafting recipe from the plateau map and it only unlocked rank 4 life on the crafting bench. On the bench it says in the area with mods still to unlock that life 5 is on plateau map. Have I missed something here? Checked all other locations for life crafts and it seems i got them all (i.e act 6, act 10 and port map) I'm very confused

Thanks