I have a linked service and I am trying to change the Azure Key Vault Reference (this is the view of authoring instance)

I am using git integration and in my authoring instance I have set it up using a key vault reference however, when I deploy this it changes it to using password (see below).

I have added the arm-template-parameters-definition.json file so it allows me to override certain values but for some reason its not keeping the key vault reference.
"Microsoft.DataFactory/factories/linkedServices": {
"*": {
"properties": {
"typeProperties": {
"baseUrl": "=",
"serviceEndpoint": "=",
"credential": {
"referenceName": "="
},
"password": {
"type": "AzureKeyVaultSecret",
"store": {
"referenceName": "=",
"type": "LinkedServiceReference"
}
}
},
"connectVia": {
"referenceName": "="
}
}
}
This is a duplicate question, I can't delete as I don't get the option but when I posted this I got a 404 response hence the duplicate question as I tried again :)