I was at 3 shops an no one give me codes. Everyone say its shoving transmision problem. Thats why i write here because no one give me answer. Somebody say it can be clutch, another say is chain on engine, another say it can be starter alternator. So i m confused, don’t know what to change. Thank you

F15 hybrid, while calm driving ( not accelerating) happens knocking , engine shutting down and driving on electricity. Need to stop and start engine for continue driving
What can be the problem? Thank you