ASP.NET Core / Kestrel not serving static content consistently

Background Info:

• ASP.NET Core v3.1 w/ RazorPages
• Works fine locally (Win10 & Kestrel on localhost)
• Returns 404 for files in wwwroot/ only on deployment to Linux VM (Ubuntu 18), Bootstrap works fine locally, no 404s
• Publishing with dotnet publish -r linux-x64
• The deployed app is running Kestrel and being forwarded requests from NGINX.

Startup.cs

public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
    /// Included before other middleware (needed due to nginx forwarding)
    /// Per: https://docs.microsoft.com/en-us/aspnet/core/host-and-deploy/linux-nginx?view=aspnetcore-3.1
    app.UseForwardedHeaders(new ForwardedHeadersOptions
    {
        ForwardedHeaders = ForwardedHeaders.XForwardedFor | ForwardedHeaders.XForwardedProto
    });

    if (env.IsDevelopment())
    {
        app.UseDeveloperExceptionPage();
    }
    else
    {
        app.UseExceptionHandler("/Error");
        app.UseHsts();
    }

    app.UseHttpsRedirection();
    app.UseStaticFiles();
    app.UseRouting();

    app.UseCookiePolicy(); // -- Added for AaaS?

    app.UseAuthentication();
    app.UseAuthorization();

    app.UseEndpoints(endpoints =>
    {
        // Added to allow controllers
        endpoints.MapControllers();

        // Original Razor Page way
        endpoints.MapRazorPages();
    });

}

_Layout_.cshtml

<head>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>@ViewData["Title"] - Title</title>
    <link rel="stylesheet" href="~/lib/bootstrap/dist/css/bootstrap.min.css" />
    <link rel="stylesheet" href="~/css/site.css" />
</head>

partial layout of wwwroot/:

• css/
  • site.css
• js/
  • site.js
• lib/
  • bootstrap/
    • dist/
    • css/
      • bootstrap.css
  • jquery/