Mystery resolved. It might be more complex in our environments due to our peculiar set up but this is how I resolved it.
The log in message is written to the Data Project. This applies to all the other set ups controlled by the "edit projects settings", as well as the "project time settings". And the data project is mastered in the Stg environment. As a result changes to any of these set ups needs to be done in the Stg environment, in the Data project, and copied to the Dev and Prod environments.
Making these changes in either the Dev or the Prod environments does not achieve the desired results and creates lots of problems with unforeseen consequences in terms of performance and configurations.