When I try to setup a Custom URL for a new google sites it says "Custom URL already taken"

Looking at Company Profile, Custom URLs There is no custom URLs set.

Where else can I look to find and release the taken www?
When I try to setup a Custom URL for a new google sites it says "Custom URL already taken"

Looking at Company Profile, Custom URLs There is no custom URLs set.

Where else can I look to find and release the taken www?