Jackson error on custom token

[mfitzwm8]

I get the following error when trying to login using a custom token containing an array:

com.fasterxml.jackson.databind.exc.MismatchedInputException: Cannot deserialize instance of java.lang.String out of START_ARRAY token at [Source: (okio.RealBufferedSource$1); line: 1, column: 212] (through reference chain: com.mongodb.stitch.core.auth.internal.models.ApiCoreUserProfile["data"]->java.util.LinkedHashMap["accountIds"])

I get a similar Jackson error if I use a nested object within the user_data property. If I revert these to simple strings etc then it succeeds.

Version: 4.5.0

JWT payload:

{ "aud": "<app_id>", "sub": "<user_id>", "iat": 1570452225, "exp": 1570458825, "user_data": { "accountIds": [ "<id_1>", "<id_2>" ] } }

Code to reproduce is based on the Sample Todo List repo with the following addition in LogonActivity.java:

private void enableCustomAuth() {
    String token = "<jwt_token>";
    findViewById(R.id.custom_login_button).setOnClickListener(ignored ->
            TodoListActivity.client.getAuth().loginWithCredential(new CustomCredential(token))
                    .addOnSuccessListener(user -> {
                        Toast.makeText(LogonActivity.this,
                                "Logged in Custom. ID: " + user.getId(),
                                Toast.LENGTH_LONG).show();
                        setResult(Activity.RESULT_OK);
                        finish();
                    })
                    .addOnFailureListener(e -> {
                        Log.d("Stitch Auth", "error logging in", e);
                        Toast.makeText(LogonActivity.this, "Failed to log in Anonymously. " +
                                        "Did you enable Anonymous Auth in your Stitch backend and copy " +
                                        "your Stitch App ID to strings.xml?",
                                Toast.LENGTH_LONG).show();
                    }));
}