Accessing a localhost IIS site via RD web client

Question

I have a website set up on my RDS server. If I connect via an RDP session, I can launch it via the Chrome browser on the session desktop without issue (as either a domain user or a domain admin). However, if I use the rdwebclient I get an error after logging into the rdwebclient and launching the published app as a domain user. I am including pics of the site as it appears in the rdwebclient, the error I get, and the error I receive in the Event Viewer. I know this has to do with authorization or permissions, because I only get this error when logging in as a domain user. I don't get this error when I log in as a domain administrator.

Event Viewer error message:

• System
  • Provider
    [ Name] ASP.NET 4.0.30319.0
  • EventID 1309
    [ Qualifiers] 32768
    Level 3
    Task 3
    Keywords 0x80000000000000
  • TimeCreated
    [ SystemTime] 2022-12-21T20:21:29.683477500Z
    EventRecordID 359855
    Channel Application
    Computer <computer_name>.<domain>.local
    Security

• EventData
  3005
  An unhandled exception has occurred.
  12/21/2022 2:21:29 PM
  12/21/2022 8:21:29 PM
  8e8fe84f030446d4a1ce13c803e0d65e
  111
  8
  0
  /LM/W3SVC/1/ROOT/RDWeb/Pages-8-133160514073834292
  Full
  /RDWeb/Pages
  C:\Windows\Web\RDWeb\Pages\
  <computer_name> 9368
  w3wp.exe
  IIS APPPOOL\RDWebAccess
  NullReferenceException
  Object reference not set to an instance of an object. at Microsoft.TerminalServices.Publishing.Portal.FormAuthentication.TSFormAuthTicketInfo..ctor(HttpContext objHttpContext) at ASP.en_us_default_aspx.<GetAppsAsync>d__0.MoveNext() --- End of stack trace from previous location where exception was thrown --- at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw() at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) at System.Web.UI.PageAsyncTaskManager.<ExecuteTasksAsync>d__3.MoveNext() --- End of stack trace from previous location where exception was thrown --- at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw() at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) at System.Web.UI.Page.<ProcessRequestAsync>d__554.MoveNext()
  https://<Server>.com:443/RDWeb/Pages/en-US/Default.aspx
  /RDWeb/Pages/en-US/Default.aspx
  <IP address> False IIS APPPOOL\RDWebAccess
  633
  IIS APPPOOL\RDWebAccess
  False
  at Microsoft.TerminalServices.Publishing.Portal.FormAuthentication.TSFormAuthTicketInfo..ctor(HttpContext objHttpContext) at ASP.en_us_default_aspx.<GetAppsAsync>d__0.MoveNext() --- End of stack trace from previous location where exception was thrown --- at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw() at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) at System.Web.UI.PageAsyncTaskManager.<ExecuteTasksAsync>d__3.MoveNext() --- End of stack trace from previous location where exception was thrown --- at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw() at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) at System.Web.UI.Page.<ProcessRequestAsync>d__554.MoveNext()