It seems something is causing the effect of the "Big Seed" treasure to appear in Naija's Home without actually getting the treasure itself. I assume some flags are running amok.
I've narrowed it down and it's either caused by the Girl's Costume or any number of flags involved in the Sunken City (or after first entering the Body, the tongue going away)
EDIT: it's not the Glowing Seed, just tested. I'm betting it's some Sunken City event flag.