Can't release credit order created from order via API

[adrianm]

Kind of a strange problem.

We create invoices from orders like:

* POST api/v3/salesorders

* POST controller/api/v2/salesorderbasic/{orderType}/{orderNumber}/action/prepareInvoice

* POST controller/api/v1/customerinvoice/{invoiceNumber}/action/release

this works fine but for not for credit invoices

* POST api/v3/salesorders

* POST controller/api/v2/salesorderbasic/{orderType}/{orderNumber}/action/prepareInvoice

* POST controller/api/v1/customerCreditNote/{creditNoteNumber}/action/release

The credit invoice is not released, no error message, but can be released in the GUI.

Also, a credit invoice created directly, i.e. not from order, can be released via API.

What can we do differently to work around this?