Hello, thank you for reaching out to Microsoft Q&A.
Have you selected the Landscape orientation, not the Landscape (Flipped) orientation in the display Settings on Windows 11?
If your laptop supports 360-degree rotation, try flipping it completely upside down and then returning it to the normal position. Check whether the screen automatically returns to the standard landscape orientation. (This may work if your laptop/tablet has orientation sensor built-in)
If the CTRL + ALT + UP Arrow keys do not work, you can simply restart your computer once and see if it returns to the normal position.
If it still doesn't work, let me know.