2H 2023 Horizon Theme is not consistent across modules

Why are modules showing different header colors and why are they not matching our Preview instance?

Post the 2H 2023 release to the Preview instance I spent several hours going through each module page and sub pages documenting all differences between 2H 2023 Horizon theme in the preview instance as compare to the 1H 2023 Horizon theme configured on our production instance. From this comparison, I created 3 SAP support tickets with 2 of them resulting in identified 'bugs' and the 3rd an enhancement request.

Now that the 2H 2023 release has been deployed to production I was expecting to see the same as from preview but I didn't. WHY? :(