The mic on my iPhone 11 intermittently drops during calls

I am facing an annoying issue on my iPhone11. Whenever I am in a call with someone, my voice drops off and comes back on intermittently while on the call. The person at the receiving end cannot hear me or my voice breaks off every few seconds while I can hear the person very clearly. It does not matter if I am using speaker, headset/headphone or talking directly on the phone. The intermittent voice drop continues to give me trouble. I checked with my service provider and they have said this is not a network issue. This issue occurs wherever I am (home, work, on the road on full network). My iPhone is updated to the latest iOS version (17.5.1). I am at my wits end on how to resolve this.

[Re-Titled by Moderator]