My face id works while laying down on my back no problem. On your side? Why would it work if your face is partially covered by the pillow? The working in landscape mode is correct, it doesn’t work. Truthfully, until you mentioned it I never even tried to unlock it that way.I honestly call bologna at everyone saying how 'flawless' FaceID is. Have you ever used it at a weird angle? Landscape mode? In your bed on your side? You're really claiming 100% accuracy here?
And I more often than not get the 'FaceID' screen before the home screen comes up.... I rarely have an experience where it instantly recognizes me.