Network &1 is assigned to controlling area &2 and not &3

What causes this issue?

You entered an account assignment to network/activity &V1&/&V4&. This
network is assigned to controlling area &V2&. However, you post to the
controlling area &V3&. This controlling area might have been derived
from the plant or the company code.

System Response

The posting is not allowed.

How to fix this error?

Enter an account assignment to a network that is assigned to
controlling area &V3&.

Error message extract from SAP system. Copyright SAP SE.