Ritual Talent "Spreading Darkness" did not work

I have "Spreading Darkness" ("Your Maps with Ritual Altars always have four Ritual Altars") talented, but I just ran a t16 corrupted map and it only had 2/2 rituals. See screenshots below. I do not see any modifier that would remove 2 rituals.

https://imgur.com/a/QOsgQb9