The alpha male Alf started feeding about a week ago.
-- Either I missed the release
-- or the babies died in his mouth
-- or he never had them.
I'm pretty sure they spawned because all the signs had pointed to it, no inconsistencies versus prior spawns, everything checked out.
I might have noted that he stopped feeding too late and the 6 weeks had elapsed 2-3 weeks earlier than I figured, but I doubt this.
The most likely reason in my mind is my slowly increasing the water hardness by 5x-10x all the while they courted, spawned, and he held the babies in his mouth. I think the fry didn't survive the hardness experiments and perished in his mouth and he, of course, spit them out. In their 4500 gal, any freebie snack like that would get picked up within seconds.
Just my analysis worth $0.02