Hey @sahbia ,
can you tell me what phone are you using and if this is affecting all your contacts? Is this happening in all areas and do you have strong network coverage on the phone when that happens?
Do the same thing happens if they call you or if you call them @sahbia ? How long have you been having this issue? Have you tried to turn the phone off, take the SIM out and rub the golden contacts, and then put it back?
