How to troubleshoot ASP.NET app never loading in IIS

Question

I have an ASP.NET app (.NET Framework) deployed to an ec2 instance running Windows Server and IIS. The app never loads in my browser - it just spins forever. This is true for .aspx pages as well as simple static .html pages.

What I've tried so far

• Loading the website as localhost from a browser on the server itself...no luck
• Website physical path is correct
• Website binding matches what I've used on other servers
  • <binding protocol="https" bindingInformation="*:443:*" sslFlags="0" />
• Windows permissions look OK (both the app pool user and IIS_IUSRS have full control)
• The app pool looks OK (Mode=Integrated; Identity=ApplicationPoolIdentity)
• Server Roles and Features look OK (Web Server role, .NET Framework 3.5/4.6 Features, etc.)
• This ASP.NET app works fine on other machines
• I created a simple "HelloWorld" website in IIS on this same server - it loads fine
• I tried adding logging to Global.asax.cs, but it seemingly never gets hit
• I don't see any traffic in IIS logs
• I don't see any obvious issues in the Windows Event Viewer (I do see lots of activity, but nothing that points to a problem with my app, as far as I can tell)
• Disabled proxy settings in Chrome
• Viewed network traffic in Chrome - the request just shows as "Pending" and never returns

This is frustrating, because I can't seem to get any logs or information about what might be the problem. How can I troubleshoot this issue?