Can't change USG default network subnet mask from /22 to /24

Somehow after an update, my controller decided to set all networks to auto scale.This resulted in my default network to become a /22 network and I can't change it back to /24.

I've tried to change it to a /21, success. I've tried to change it to /23 or /24 and it fails.The error it throws at me is: "Failed saving network "Management". This fixed IP address is not valid. Please try another IP address.

The thing is: There is no DHCP server active. There are no static routes pointing to anything beyond x.x.x.254, There are no portforward rules and there are no other unifi devices that are outside of the /24 network.

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Why is this error being thrown at me when I'm trying to make my network smaller?

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EDIT*: Also no IP Groups that contain any addresses beyond x.x.0.254