Powdery Mildew issues

Does anyone have a serious solution for powdery mildew? I've tried everything and I'm so fed up of almost every single grow having this issue. I have 3 different fans, and a dehumidifier keeping conditions under 60% at all times and yet, the PM always comes around like mid flower. There is plenty of airflow in the tent and my plants are not bushy at all to create air pockets. I'm desperate a serious solution so i dont keep having my grows ruined. Please help

Edit: I've tried using a peroxide spray and have had 0 luck still with getting rid of the issue/ preventing it