Zero Trust DNS location IP cannot be saved

Additional information

I don’t know/other

What is the error message?

These networks overlap networks that are in use by another Gateway customer

What is the issue you’re encountering

Hi, when adding my own IP address in Zero Trust → Gateway → DNS location. It shows “These networks overlap networks that are in use by another Gateway customer” and can not be saved. FYI, I have owned this external static IP & its not a public IP. Please resolve this issue as I am in free plan.

Screenshot of the error