AnshulRai Hey mate,
What service/app are you using for these work calls?
Can you see whether it’s changing the primary mic/speaker source from Nothing Ear to something else during the times where you can’t hear someone else?
Is the same behaviour across all calls i.e. phone calls, zoom calls, whatsapp calls, teams calls?
Does a reset of your Nothing Ear’s fix the issue (resetting via the Nothing app)