I am a fairly new user. On my most recent flights, ATC gives me a heading, I dial it into autopilot and fly the heading. Then, even though I am flying the heading, it both tells me I am off course (I am not) and then tells me to fly the heading I am already flying, over and over and over again.Sometimes it likes to combine the above with an instruction to fly the heading I'm on (that it doesn't see me on anyway) and to go direct when able even though the heading that I am on is the direct FMC heading.Is it me?