I am not sure what is going on but I have noticed it more while crouched.

the W and S Forward and back keys mysteriously switch. When I press W I expect to go in the direction I am facing not back up.

Is this a bug or something that is happening because of some game mechanic?

Noticed the same thing, although I'm thinking it's just "twisted". If you untarget and move the character, the whole map "untwists" to go the correct direction. I think the "follow target" setting has something to do with this. Almost like it's setting the view to move, and the character "twists" with it, but the controls are still facing a different direction. Wonder if I could look at the feet and tell which way I was pointing?