Plaid MFA response incorrect using long tail institution

Question

I am using plaid service and I'm trying to initiate a "step" call on the "Mountain America Credit Union" which from the longtail search.

When It's ask for mfa(Question based) then on entering wrong answer sometimes it allows me to register successfully or give response listed below:

Response:{
   code = 1200;
   message = "invalid credentials";
   resolve = "The username or password provided were not correct."
}

Thing is that for entering wrong mfa response from plaid

Response:{
    code = 1203;
    message = "invalid mfa";
    resolve = "The MFA response provided was not correct.";
}

Why for longtail search I am getting this error?

Any one have faced this issue? if yes please help me

Thanks