When I switch to landscape mode (NUMPAD 7 or CTRL+F11) the emulator rotates the screen to landscape orientation but the Android OS and none
In my case the Skin option in AVD settings was the problem. When I selected "No skin", it worked.
In my case you need to click a small button that would enable the orientation to change, right after you press the main change orientation button.
Once you click the change orientation button, a small icon displays on the emulator asking if you want to change the orientation of the emulated screen. It only displays for a few seconds, so look next to the "bottom" icons and you will see this temporary icon.
This works with the emulator keyboard on or off.
I am running Pixel 2 API 29, Android 10.0 (latest versions as at today)
I had the same problem, I instantly fixed it by simply deleting the device from the AVD list and just creating a new one.
API Level 29 here. By default the rotate is disabled. Pull Down the drop-down of the mobile and enable it.
You have to use Android 5.1.1, aka API 22, aka Android 5.1 LOLLIPOP_MR1. Download Android 5.1.1 (API 22) in your Android SDK Manager and when you create a new Android Virtual Device select that as your OS.
As war_Hero mentioned, this bug was reported to Google. The bug is now fixed as of Mar 23 '15:
https://code.google.com/p/android/issues/detail?id=61671