iphone 12 pro max inbound calls not working

Is this all inbound calls, or just calls for those individuals that are not in your contacts. if callers not in your contacts, check Settings>Phone>Silence Unknown Callers and turn that off. If all callers, check Do Not Disturb and make sure that is not on. Also, check Settings>Phone>Call Forwarding, make sure that is off too. If they are off, then contact your carrier for assistance. They handle calls.