issue with onelogin_saml_apps parameters block

[pmoosh]

I am trying to set a parameter for a saml app:

resource onelogin_saml_apps this {
  connector_id = 110016 # SAML 2.0 Advanced connector ID
  name =  "testonelogin"
  description = "test"

  configuration = {
      signature_algorithm = null
      saml_notonorafter = "3"
      consumer_url = "${local.base_url}/saml2/acs/"
      login = "${local.base_url}/saml2/acs/"
      audience        = "http://test.com/"
      generate_attribute_value_tags = "0"
      saml_initiater_id = "0"
      saml_notbefore = "3"
      saml_issuer_type = "0"
      saml_sign_element = "0"
      encrypt_assertion = "0"

      saml_sessionnotonorafter = "1440"
      saml_encryption_method_id = "0"
      recipient = "${local.base_url}/saml2/acs/"
      validator = ".*"
      relaystate = "${local.base_url}/"
      saml_nameid_format_id = 0
  }
  parameters {
      include_in_saml_assertion = true
      param_key_name = "urn:mace:dir:attribute-def:cn"
      user_attribute_mappings = "firstname"
    }
}

I might be doing it wrong but for some reason it does not set the user_attribute_mappings
Also when I run apply twice terraform crashes ( I guess it is not supported - just wish it wouldn't crash)....
terraform version used: 0.14.3 and 0.14.9