Implementing passwordless with ASP.NET Core

I’m trying to get passwordless working using ASP.NET Core, but can’t seem to figure out what I’m missing. I might not understand the flow 100%

I have regular OpenIdConnect auth working with ASP.NET Core, have also tried following the guide and sample here: - logging in using username/password - everything works great

I’m then trying to follow this guide:

And I can enter an e-mail address and the received code and I’m redirected back to the /callback uri, that is where it stops working.

Using passwordless it seems that the state query parameter is way too short compared to the regular ASP.NET Core challenge flow. This causes ASP.NET Core authentication handler to reject the state.

Is there a sample somewhere showing how ASP.NET Core and the passwordless flow should be configured?