AshForce

Good Evening, I have a BMW 640D for over 8 years 2016 done 85 K, bought it pretty much new from the garage, recently when I am stationary in traffic with automatic start / Stop and the engine is off, the car would automatically drop out of Drive into Neutral or park. This happened once a while, but recently I started to get the error "Transmission : Drive moderately" for a few seconds each time and it will disappear. Today I decided to put the car in sports mode and the car went into Neutral and the error came, I put the car back into normal mode after 1/2 mile and now I have the engine light persistently on. I have no loss of power and no other issues. The car hasnt had a transmission oil change or top up. I service it regularly and keep it in good condition as possible. Any advice? any recommendations will be greatly appreciated. I am based near Romford Essex, or a reputable garage I can take it to.