For the sake of data this is the 6th time my ship has come back from 21 > 22 and still no Diadem hardmode. This ship does has a tatanora piece and has since it hit 50 months before the Diadem came out. I had another ship with a tatanora pice do 17 - 18, and nothing.

SE clearly just wants the salt of my tears for their fries.