Just got the tmobile android 12 update on my Oneplus 9pro global version and its causing issues

That's odd.  Disabling automatic system updates should stop it from installing regardless of the time.  That is all I do to prevent the next update, even though I do see the notification for it, which I ignore.  If it annoys you to see it in the bar, then go to Settings, Apps, Show System Apps, and force close system Updater.  As soon as you reboot the device though, it will pop back up that the update is available.