Login screen appears on extended monitor

When I upgraded my 2014 mini to a 2023 M2 Pro mini with a new Studio Display; I used the 27" Thunderbolt Display, that I had used with the 2014 mini, as an extended display for the M2 Pro mini. I used an Apple Thunderbolt 3/USB-C to miniDP adapter with the TB/miniDP cable to connect to the TB Display and the TB3/USB-C cable that came with the Studio Display to connect to it. I have two admin accounts as users, myself as primary Admin and my wife as a secondary Admin. The Login screen for my account would appear on the extended screen at startup, restarts, and also when waking from sleep after logging out. I searched the Community forums and found this post that helped me resolve this issue.

"Login screen appears on wrong monitor - Apple Community

Below is a Reply that the Author posted on July 4, 2022 to his original post/question on May 25, 2022:

"A user in an another forum gave me the final hint to this Login-Riddle (thanks again Maniacintosh). Like him I am using two accounts on my Mac Studio. An Adminaccount for maintenance and a Standarduser which I work the most time with. So I confiugred my monitors just with the Standardaccount.

The solution was actually very simple: I had to login to my Adminaccount to configure the monitors the same way as in the Standardaccount and that's it. After a fresh boot or a reboot the login screen finally appears on my configured main monitor."

In my case I needed to login to the second Admin user account and configure the Display settings to be the same as in the primary Admin user account. Even creating a 'test' standard user account had the login screen on the extended monitor until all users were configured the same.

Even a phone call to Apple Support online and a trip to an Apple Store Genius Bar did not help resolve this issue. In fairness, we (the experts & I) didn't think about considering the another user account as the source of the 'conflict'.