Vibrating the fork with hard brake

Hi guys, maybe one of you can help me. Have the following problem with hard braking starts vibrating my fork what could that be? Could that have to do with the setting of the fork because it is completely open in relation to spring prestress, to be approximately adjusted to my weight correctly? Anything else concerning wear and tear I can actually exclude because the bike is not even a year old. Maybe someone has a suggestion ag what else it could be. Thanks already in advance.