Running out of existing IP subnet range

What version of code are you using? If it is a new enough version, just go into the GUI and change the netmask. It allows you to do this.

If not, I would create a new selfIP with a different address and /22. Then delete your /24. Then, create a new selfIP with the old address and /22.

Example. You now have 10.10.1.1/24 Create 10.10.1.2/22 delete 10.10.1.1/24 create 10.10.1.1/22 delete 10.10.1.2/22

Now you have 10.10.1.1/22