Samsung
Change Always On Display Orientation auf Samsung
The Always On Display on Samsung phones follows the phone's default lock screen orientation, which is portrait. That works for pocket or nightstand use, but if you keep the phone in a horizontal dock, car mount, or flat stand, the clock and notification icons stay rotated on their side.
One UI includes a dedicated orientation setting inside the Always On Display menu, separate from the general screen rotation option. Changing it does not affect how the interface behaves once you wake the phone; it only controls the layout while the screen is off and the Always On Display is active.
Open Settings ➔ Lock screen ➔ Always On Display ➔ Screen orientation and pick Portrait or Landscape.
If the orientation option is missing, check whether Always On Display is turned on at all. The screen orientation menu only shows up once the feature itself is active, so devices with it disabled won't display this setting.