I am having a problem that sometimes (happens at least once a flight) when I am approaching a waypoint (generally a STAR but not always) the autopilot switches into heading mode from nav mode. I am currently running 1.0.9 however this has been happening from the beginning I thought I was doing something wrong but I cannot seam to figure out what it is so I am not sure if it is a bug or me doing something incorrectly. Is anyone else having the same problem or can tell me what I am doing wrong?
Steps I use to setup autopilot not including entering the flight plan.
Flight Director - On
Heading mode - On for runway heading
Once i'm around 1000 feet I switch to nav mode
Set and enable vertical speed