I have an iCloud contact called 'Mum'. Every time I use my Mac, this contact is renamed 'Mum Mum', including on my iPhone, as it's an iCloud contact. This isn't happening with other contacts with only a first name. I'm not sure if this is when I send an email to this contact from Mail on my Mac, or open Contacts on my Mac.
I would really appreciate any help or advice on this!