iPhone 7 (iOS 15.1.2) microphone is not working on WhatsApp/Instagram calls

Hello, I have recently upgraded the software of my iPhone 7. Now other party says that he/she is unable to listen my voice but when I put my phone on speaker they are able to listen my voice on WhatsApp calls as well as Instagram calls whereas if I use FaceTime it works perfectly fine without any hassle. Also if I use Siri it works fine on Siri as well. Please provide me the solution as it is annoying me badly and forcing me to turn on the speaker while talking to people. I did all the fixes guided on YouTube but of no use.