MFA via SMS: "could not find a strategy to login with" error during Step-up Authentication (AAL2)

[resulbdev]

Describe the issue: I am trying to implement MFA via SMS on a self-hosted Ory Kratos instance. Although the identity has both password and code credentials, and the SMS Courier is configured via HTTP messenger, I am unable to trigger the SMS code sending. I keep receiving the error: could not find a strategy to login with.

kratos.yml

selfservice: methods: code: enabled: true config: mfa_enabled: true courier: http: request_config: url: https://test-identity.dev/api/v1/auth/sms/simulate method: POST body: base64://ZnVuY3Rpb24oY3R4KSB7CiAgY29kZTogY3R4LnZlcmlmaWNhdGlvbl9jb2RlCn0=

schema.json

"phone": { "type": "string", "format": "tel", "ory.sh/kratos": { "credentials": { "code": { "identifier": true, "via": "sms" } } } }

Steps to Reproduce:

Perform a successful AAL1 login using password.

Initialize a new login flow for AAL2: /self-service/login/api?aal=aal2&refresh=true.

Submit the code method with the identifier:

Bash

curl -X POST .../self-service/login?flow=
-H "X-Session-Token: "
-d '{"method": "code", "identifier": "+90555...", "via": "sms"}'

Actual Behavior: The API returns a 400 Bad Request with the message: could not find a strategy to login with. The ui.nodes in the flow remain empty or do not show the code input fields.

Log Output: level=info msg=Encountered self-service login error. audience=audit error=map[message:I[#/] S[] could not find a strategy to login with] ... requested_aal=aal2 state=choose_method

Additional Context: I have verified that the identity traits and the login identifier match exactly. I've also tried adding resend: sms but the result is the same. The courier logs do not show any attempt to send a request to the HTTP messenger.