Unable to upload more files with inputFile in ADF 12.2.1.3.0

We are using ADF 12.2.1.3.0 and trying to implement multiple file upload. I configured <af:inputFile> with maximumFiles="0" for multi‑file upload, but I cannot access the uploaded files:

• The value binding (#{ProcessFileBean.uploadedFiles}) is always null.
• The component binding (RichInputFile.getValue()) also returns null.

My setup:

 <af:inputFile label="File" id="if2" simple="true" binding="#{ProcessFileBean.inputFiles}"

                          contentStyle="height: 85px; width: 169px; background-image: url('images/uploadFileBackground.jpg'); background-size: cover; color: White;"

                          styleClass="orderAttachmentCustomStyleClass" value="#{ProcessFileBean.uploadedFiles}"

                          rendered="#{ProcessFileBean.fileType eq 'ap'}" maximumFiles="0"/>

Bean:

    public void setInputFiles(RichInputFile inputFiles) {

        this.inputFiles = inputFiles;

    }


    public RichInputFile getInputFiles() {

        return inputFiles;

    }


    public void setUploadedFiles(List<UploadedFile> uploadedFIles) {