There's two components in a turn - the desired heading at the end of the turn, and the direction you should turn to get there. Setting the "Climb to" altitude a

There's two components in a turn - the desired heading at the end of the turn, and the direction you should turn to get there. Setting the "Climb to" altitude appears to have cleared the turn direction information. In the absence of that, the computer will turn in whichever direction results in a shorter turn to the desired heading. This is usually what you want, but not always, so I can understand it taking a while before anyone noticed it.