Lava Geode Stack Not Placing?

Hi, all, again. I have my marker block spawning for my feature stack. I'm trying to get my "geode" to spawn but I am encountering some issues. 
Problem is, I don't know what the issue that's preventing it from spawning is. I did check the error log for this, but there's no errors listed, so I've come here. I've attached screenshots of the relevant files to help.
I've tried block columns and simple blocks as well, so I know it's probably not the type of feature that's the issue.
I did get disks working the other day, so I'm not certain why I'm having trouble here.