Pass collection variable from LWC back to Flow

I have my own LWC component in my flow. The LWC component returns an array at the end with several entries of the type "Requested_Spare_Part__c". I have also configured the meta.xml as follows: 

<?xml version="1.0" encoding="UTF-8"?><LightningComponentBundle xmlns="http://soap.sforce.com/2006/04/metadata">    <apiVersion>59.0</apiVersion>    <isExposed>true</isExposed>    <targets>        <target>lightning__FlowScreen</target>    </targets>    <targetConfigs>        <targetConfig targets="lightning__FlowScreen">            <property name="outputVariable" type="@salesforce/schema/Requested_Spare_Part__c[]"                role="outputOnly"                label="Output Variable array"                description="The output variable that will be used to pass data to the flow." />        </targetConfig>    </targetConfigs></LightningComponentBundle>

So far everything compiles correctly, but the output in the flow does not meet the expectations. In the browser console, the output looks like this:

[    {        "Spare_Part__c": "01t5p00000COqi9AAD",        "Quantity__c": 1    },    {        "Spare_Part__c": "01t5p00000COqnAAAT",        "Quantity__c": 1    }]

But in the flow like this:

Lightning Component: testcompScreen component: c:createRequestedSparePartInputs:Outputs:outputVariable = requestedSpareParts2BCreated ([[Requested_Spare_Part__c (Spare_Part__c:01t5p00000COqi9AAD, Quantity__c:1)], [Requested_Spare_Part__c (Spare_Part__c:01t5p00000COqnAAAT, Quantity__c:1)]])

So I cannot iterate over the list and enrich it with further data. Because the list outputs null when iterating. This does not correspond to the definition of the variable:

Data Type: Record

Object: Requested Spare Part

Allow multiple values (collection) = true

What am I doing wrong? Where is the error?

#Salesforce Developer