Azure Workbook not fetching data from custom endpoint despite CORS enabled

Question

I'm using an Azure Function App as a custom endpoint for my Azure Workbook.

However, I've noticed that my Workbook is unable to fetch data from the function app, complaining that CORS isn't enabled:

Yet CORS is enabled, and for the sake of testing, I've allowed all origins:

Is there something else I can do? Or another thing to debug?

TIA!

P.S: I've tried from my Postman, the endpoint is working as expected.

Answer 1

It turns out that this little setting was enabled for some reason:

So, the OPTIONS preflight request wasn't going through. Anyways, problem is now solved.

Thanks for the heads up @John