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Wife's Samsung S9 rings but when you press to answer you can hear the caller but they can't hear us? Any help would be really helpful
As Vodafone recommend in this thread: Network Issues It would be worth trying your Wife's SIM in your phone, at least this would give an indication of a phone, SIM or network issue.
If this is a phone fault follow this link: Repairs
For a SIM fault follow this link: Replacement SIM cards