iPhone recording voice memos all on its own

My wife has a brand new iPhone 16 Pro Max and since the 18 update, it has randomly recorded voice memos. It will record voice memos when the phone is just sitting all by itself or sometimes when it is in her pocket. We have had the phone tested for Hardware issues and for software issues and Apple cannot find anything wrong yet this issue continues. Does anybody know a solution to this problem? Has anybody sought help from Apple for this?