Same with mine. I have to press the trip button just after start up or wait for it to go to sleep.Another quirk: after driving all day yesterday without switching off, the time and distance service overdue warnings reappeared after having been turned off with the trip switch technique at the start of the trip - probably eight or nine hours.
The technique wouldn't clear them for the rest of the trip. This morning the technique worked again. I should have tried turning off and restarting yesterday to see whether that is what made the difference.