Xbox series X controllers using same profile

When both controllers are powered on they connect to my Xbox Series X with no problem, but both control the same profile at the same time. Both control the home screen and if I go to a multi player game, the game doesn't recognize that there are two players. Both controllers can be used at the same time to control one profile/player, but there is no way to make the controllers work independently on different profiles.

Here is some additional info:

- I have multiple profiles on my Series X console, and I have two new controllers..the one that came with and a new Series S/X controller.

- The first time I connected the new controller everything worked fine. Picked a profile when it prompted, and we played Halo for hours without issue. No deliberate changes were made to configurations since then.

- I do not have the controllers assigned to a profile by default, and they are not configured to automatically sign in (set to "Nobody")

- When powered on, neither controller prompts for a profile anymore. They just automatically connect to whatever profile is signed in on the home screen.

- If I manually assign a different profile to each of the controllers in the configuration menu, it shows that they are assigned but they still both control the screen. Makes no difference.

- I do not have "copilot" enabled on either controller (never used that feature)

- I have reset the console to factory settings twice (saving games and apps), but it didn't help.

- I have removed batteries from controllers, resynced (holding down sync button on console and controller), and tried connecting with a USB cable....no change..

- I have powered down the console with the button on the front, and unplugged it for a while...no change

- Probably just a coincidence, but I discovered the issue just after I purchased GamePass Ultimate for my son. He downloaded a couple games and played online with friends, but didn't mess with console settings.

I'm out of ideas. Please advise!

:)