Malfunctioning Microphone

Hi, my name is Aris. Since about early October, my microphone has not been working properly. I cannot record voice memos, I can’t make video calls or voice calls on apps like WhatsApp, same goes with normal calls. I’d usually have to restart my iPhone or hard reset my iPhone to fix this microphone issue, but it’s usually just a temporary fix. then in some hours it goes back to malfunctioning again. I’ve tried resetting my iPhone settings to default, it was also just a temporary fix. And there are quite a lot of iPhone users with this problem, I’ve also upgraded to the latest iOS 14.2 and still no fix. I use an iPhone 7 Plus. Please help, this is not doing my iPhone experience any good.