Gear Shifting Issue after the Servise

I did the serviced the car (Body wash and engine oil change) last week and washed the engine by use of water. After the service, the gear indicator in the dash board start to flash at the "D" position and the car is pulling forward as previous. However, when there is no issue when the car start to go and read the speed about 40kmph. Therefore, I used to pick up the car at Gear position "01" and shift the gear to "D" after reaching 40kmph. There is noise coming from the gear box at this transmission point.

Furthermore, there is a little improvement after 3 days but problem remain as it is.

Can you please advise.

Thank you in advance.