It was definitely the SIM because I swapped it over to my father's phone on Monday and it failed to work in his phone (his SIM worked in my phone). On mine and my father's phone it came up with no SIM card inserted.
The new SIM is detected but says emergency calls only. It looks like some sort of account or configuration issue to me.
My handset is a Hafury GT20. I can't remember what my father's handset is.
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