Unable to hear voice on calls, speakers are working. Unable to hear on WhatsApp call also

I updated my IPhone 7 to IOS 14.3 two days ago and since then when I receive a call I am unable to hear the caller and the speaker button during the call is greyed out. The caller is also unable to hear when I speak. I checked the speaker and it works when I play music. Unable to hear on WhatsApp call also. I checked there’s is no issue with network also. My phone was working perfectly fine before the update. Does anyone know how I can fix this.