NOP 4.1 Guest Checkout error

I am getting sent to an error page when I click the "checkout as guest"

https://myrealmobile.com/checkout/billingaddress

According to the log


fail: Microsoft.AspNetCore.Diagnostics.ExceptionHandlerMiddleware[3]
      An exception was thrown attempting to execute the error handler.
System.ArgumentNullException: Value cannot be null.
Parameter name: form
   at Nop.Web.Framework.Infrastructure.Extensions.ApplicationBuilderExtensions.<>c.<UseNopExceptionHandler>b__1_1(HttpContext context) in C:\andrei\nopcommerce\sources\src\Presentation\Nop.Web.Framework\Infrastructure\Extensions\ApplicationBuilderExtensions.cs:line 83
   at Microsoft.AspNetCore.Diagnostics.ExceptionHandlerMiddleware.Invoke(HttpContext context)
fail: Microsoft.AspNetCore.Diagnostics.ExceptionHandlerMiddleware[1]
      An unhandled exception has occurred while executing the request.
System.ArgumentNullException: Value cannot be null.


I am not sure what this means but how can it be looking for a value that is null if this is for an outside guest which has not entered any info?

Has anyone come across this issue?

Thanks

Have you customise the solution

Are you able to reproduce your problem in the official demo site http://demo.nopcommerce.com/ or only on your site?

You can always search the forums for help https://www.nopcommerce.com/boards/search.aspx?searchterms=checkout+as+guest

Thanks. working on it.

Demo site works as it should.

We have no customization on our site.