Error while creating new entry in CDS View

I have created a service, below is the structure:

I am fetching data successfully from that service. Then displaying as a Smart table, as indicated below:

<smartTable:SmartTable id="detailRecordsSmartTable" entitySet="ZI_BSLiquidityGroups" smartFilterId="" tableType="Table" 
            useExportToExcel="true" beforeExport="onBeforeExport" useVariantManagement="true" 
            useTablePersonalisation="true" 
            header="" 
            showRowCount="true" 
            persistencyKey="DetailRecordsSmartTable_persistency" 
            enableAutoBinding="true" 
            class="sapUiResponsiveContentPadding"       
            customData:useSmartField="true"          
            editTogglable="true" 
            editable="false"
            initiallyVisibleFields="Bukrs,Azdat,Ktonr,Belnr,Kukey,Esnum,Vgman,Texts,Lqpos,Texts,Kwbtr"
            beforeRebindTable=".onBeforeRebind">

Table has an additional button, to create new entries. Since the smart table control it has enabled the auto binding, I have created a popup to enter the data, and once user hits save, below code gets triggered for the Create:

onSaveDialog : function () {
        var oModel = this.getModel(),
            data = {};

        data.Bukrs = this.getView().getModel("InputData").getProperty("/Bukrs");
        data.Kotnr = this.getView().getModel("InputData").getProperty("/Kotnr");
        data.Azdat = this.getView().getModel("InputData").getProperty("/Azdat");
        //data.Belnr = "111";
        //data.Kukey = "222";
        //data.Esnum = "333";
        data.Kwaer = this.getView().getModel("InputData").getProperty("/Kwaer");
        data.Kwbtr = this.getView().getModel("InputData").getProperty("/Kwbtr");
        data.Texts = this.getView().getModel("InputData").getProperty("/Texts");
        data.Lqpos = this.getView().getModel("InputData").getProperty("/Lqpos");
        data.Zregcl = this.getView().getModel("InputData").getProperty("/Zregcl");
        data.Zregfe = this.getView().getModel("InputData").getProperty("/Zregfe");
        data.Zregus = this.getView().getModel("InputData").getProperty("/Zregus");
        
        // Create a new entry through the table's list binding
        //oModel.setHeaders({"content-type" : "application/json;charset=utf-8"})
        oModel.setHeaders({
            "content-type" : "application/json;type=entry;charset=utf-8"})
        oModel.create( 
                "/ZI_BSLiquidityGroups", data
                , null, {
                success : function(oData, response) {
                    console.log("Create successfull");
            },
                error : function(oError) {
                    console.log(oError.responseText)
                    var msg = oError.responseText.split('message')[3];
                    MessageToast.show(msg);
            }
        });
        
        //oModel.submitChanges();
        this.byId("AddDialog").close();
        this.getView().byId("detailRecordsSmartTable").rebindTable(true);

        // Trigger event so Master View gets updated with latest changes
        var oEventBus = this.getOwnerComponent().getEventBus();
        oEventBus.publish("DetailTable", "Updated", this);  

        var msg = this.getView().getModel("i18n").getResourceBundle("detail.newRecordSaved");
        MessageToast.show(msg); 
    },

But no matter what I try, I always get the same response:

xmlns="http://schemas.microsoft.com/ado/2007/08/dataservices/metadata">005056A509B11EE3AEB5819C07C69E2FThe server is refusing to process the request because the entity has an unsupported format

Does anyone have any idea on what I am doing wrong here? I just can't find it

Regards, Martin

Solved by myself. Issue was a wrong parameter being passed to the create method. The null shouldn't be there