Can’t craft Mantle of Stars (Astral Sorcery, 1.16.5)

(Running on a smaller modpack, which has Astral Sorcery as its main focus. Can I still ask here?)

Starlight levels on the Altar do reach the required amount during the night, and it will detect that the recipe is in place when below that. But when there is enough starlight, it suddenly claims there's no output to the recipe (Normally it shows up on the right-hand side of the window, and this does not), and won't begin crafting at all.

I have 4 relays set up on the structure's surface, previously I had 8 and tried removing them to see if it needed the exact number. I have at least one attuned crystal I tried placing into the altar to see if it would help, and it did not. I have also placed the items by hand before trying JEI's auto-place; neither of those changed the situation.

Everything should be in place, and it seems like the game knows it, but the process won't even begin. Do I need to find all the Faint constellations first or something? Can anyone advise?