hill start assistent

heya so my car showed a message saying hill start assistant not working. I was driving up a steep hill on the peak the car slowed down and i barely made it up then it showed that message. After the car kinda wobbled while driving and it had struggle pulling. after driving on a flat area for awhile it was fine then. But im worried it will happen again and sometimes the engine makes that sound again of struggling.

my car is a diesel from 2014 I was in a car repair but they said system is not giving any signs of a problem. So anyone has ideas what it could be?