[Bug]: request to get document fails with "API backend third part service error"

### Affected Service Domain

Business Registry

### Environment

Sandbox / Dev / Test

### Affected Endpoint

GET https://sandbox.api.connect.gov.bc.ca/registry-search/api/v1/businesses/FM0299866/documents/qS6DvDssS

### Bug Description

Expected result: the document is returned

Actual result:
{
"errorMessage": "API backend third party service error.",
"rootCause": ""
}

### Steps to Reproduce & Payload

1. Call endpoint https://sandbox.api.connect.gov.bc.ca/registry-search/api/v1/businesses/BC1203189/documents/requests with payload
{
"documentAccessRequest": {
"documents": [
{
"type": "BUSINESS_SUMMARY_FILING_HISTORY"
}
]
}
}

--> above request returns a document key YLYQbkHfP
3. call https://sandbox.api.connect.gov.bc.ca/registry-search/api/v1/businesses/{{businessIdentifier}}/documents/{{documentKey}}
--> returns an error response
{
"errorMessage": "API backend third party service error.",
"rootCause": "message:Invalid request format, one or more fields have an unexpected value or structure. "
}
4. likewise, the call to get the pdf fails: call to https://sandbox.api.connect.gov.bc.ca/registry-search/api/v1/businesses/BC1203189/documents/YLYQbkHfP
-->returns an error response
{
"errorMessage": "API backend third party service error.",
"rootCause": ""
}

### Expected Behavior

Not an error

### Transaction / Correlation ID (If available)

_No response_