"Establish Regional Governance" decision not working

Started a game as the Sapa Inca hoping to convert the realm from Kamachiy over to Ayllu but for whatever the decision does nothing when I take it; government type doesn't change, I'm not able to create duchies or other higher tier titles, the decision just stays on my list of decisions as if I didn't click it, minus the prestige and influence I spent to do it; do folks have any insight into why this might be the case? I'm playing with mods but I have no idea why any of them would effect an isolated decision like this. Any help or troubleshooting thoughts are appreciated!