.NET 8 Isolated example, swagger ui wont render but I see the endpoints listed in the runtime window

**Describe the issue**
following this example
https://github.com/Azure/azure-functions-openapi-extension/blob/main/docs/enable-open-api-endpoints-out-of-proc.md

Only thing I added to my program.cs was
`.ConfigureFunctionsWorkerDefaults(worker => worker.UseNewtonsoftJson())`

**To Reproduce**
Setup a new Azure v4 function app using .net 8 isolated
Add the references like in the example for out-of-proc examples
Add the attributes to my function

I can see the swagger ui url getting called in the execution window, but the browser window is completely blank.

**Expected behavior**
Show swagger ui, but when I go the the swagger url, I see only a blank screen
.