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Clanking noise in front wheels when turn the car

Mercedes ML350 Bluetech 2015 30000km
When I make a right hand turn mainly but also left turn both at low speed, there is a “clank” or “knock” noise (only once) in front wheels. The noise does not happen every time I turn right or left. Mainly when the car starts moving after a long parking time. Sometimes the “knock” noise happens when the car is moving at 40-50 km/h and the brake pedal is pressed hard. I went in the car service, but the mechanic did not find anything unusual after removing the under cover.
Recently there is a vibration noise in the cabin coming from the steering wheel. This happens when the steering wheel is in free position, the car is full stopped and the engine is running. I opened the engine cover and vibration noise stopped when I pressed the intermediate shaft of the steering.
Anyone know what would cause this? Thank you.