Late in Game, Still Cannot Upgrade Familiars

Hey team, I'm what I suspect is fairly late in the game, having defeated Cronos and Typhon enough times that I was able to convince Cronos to change his ways (night ~60, like 30 successful runs in a row now both up and down).

I've got the first three familiars (cat, bird, toad) and have used all available cauldron things (including making beast-loved morsels x4). I've done escapes with each of the three. Hecubua recently told me I could start seeking out her familiars to bond with them as well, but I haven't seen them since.

And yet... I can't upgrade my familiars. My only interaction options are petting or talking / taking with me.

Is there something I'm missing or haven't unlocked, or is it possible that I've hit a bug of some kind?

Appreciate any help.