Occasionally Power will not allow users to update their settings. This is a cached data issue HOWEVER it cannot always be resolved by clearing cache & cookies.
In order to resolve this issue, the user needs to log in to power from a private browser or incognito browsing session and update the settings to either include, or no longer include Canadian loads. (or similar results).
Once toggled, create a search in Power while in the private or incognito session, confirm the fix, then log out and back in to Power in the normal browser and confirm the fix has persisted.
Making the change in the private/incognito session tricks the system in to overwriting previous data which is not cleared by clearing cache and cookies.