SelectedFilesChanged event never fires on DxUpload component for Blazor

I tried implementing the file uploader component from DevExpress like this:

@inject NavigationManager NavigationManager<div id="file-upload-dropzone" class="card custom-dropzone rounded-3 w-100 m-0"><span class="drop-file-icon mb-3"></span><span class="drop-file-label">Drop image(s) anywhere to upload</span><span class="m-1">or</span><DxButton Id="file-upload-browse-button"              CssClass="m-1"              RenderStyle="ButtonRenderStyle.Primary"              Text="Browse" /></div><DxUpload Name="file"          Visible="@UploadVisible"          ExternalSelectButtonCssSelector="#file-upload-browse-button"          ExternalDropZoneCssSelector="#file-upload-dropzone"          ExternalDropZoneDragOverCssClass="custom-dropzone-hover"          UploadUrl="https://localhost:7226/api/Upload/Upload/"          SelectedFilesChanged="@SelectedFilesChanged"          MaxFileSize="15000000"></DxUpload>@code {    bool UploadVisible { get; set; } = false;    protected void SelectedFilesChanged(IEnumerable<UploadFileInfo> files)    {        UploadVisible = files.ToList().Count > 0;        InvokeAsync(StateHasChanged);    }    protected string GetUploadUrl(string url)    {        var test = NavigationManager.ToAbsoluteUri(url).AbsoluteUri;        return test;    }}

The styling is great, and the windows file-selector window opens when I click the button, but the SelectedFilesChanged event never fires.

I basically followed the exact example here.

What have I missed?