LoginAsync fails after update to 3.1.2

Hopefully this is the right place for this!

We have just updated from 2.9.0 to 3.1.2, and the login now fails. Looking into the identityServer logs we are seeing the following

Invalid grant type for client: "authorization_code"

We have changed nothing on either the client (iOS), or on IdentityServer4.

I’ve compared the 2.9.0 -> 3.1.2 tags on git, but can’t see anything obvious that might be causing this. https://github.com/IdentityModel/IdentityModel.OidcClient/compare/97055bd...de3c5ee

Info

IdentityServer4 version: 2.2.0 Updated OidcClient version: 3.1.2 Oidc Flow: Hybrid on iOS

Request Content

This is the content that idSrv receives when making the login request

{
  "ClientId": "iOS",
  "ClientName": "iOS App",
  "RedirectUri": "com.<OMITTED>://auth",
  "AllowedRedirectUris": [
    "com.<OMITTED>://auth"
  ],
  "SubjectId": "anonymous",
  "ResponseType": "code",
  "ResponseMode": "query",
  "GrantType": "authorization_code",
  "RequestedScopes": "",
  "State": "4c8cHL5TGl8XETmaw92a",
  "Raw": {
    "response_type": "code",
    "nonce": "i82GNeiwertgfdwe34rGIg",
    "state": "4c8cHL52345TGl8XEmbTp",
    "code_challenge": "EB7LmP9r4Td_uihPAXwqoAN1wZAx",
    "code_challenge_method": "S256",
    "client_id": "iOS",
    "scope": "openid profile api offline_access",
    "redirect_uri": "com.<OMITTED>://auth"
  }
}

[leastprivilege]

That’s correct.

[github-actions[bot]]

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