UK Settlement visa issued on document rather than passport

[Malindian]

Hello all,

My wife applied for settlement visa in Kenya which has been granted thankfully, however the UK does not recognise a somali passport and has issued the visa on a an A4 document.

My understanding is this also happens where the applicant is a refugee or in this case both.

I would really appreciate some help from anyone who has either been through this or similar situation or has knowledge on the process of immigration i.e exit from the country of origin and how this generally works?

Many thanks