Protocol/openid-connect/token return HTTP 500 instead of HTTP 400 with invalid refresh_token

Since relase 20.0.1, when calling updateToken from keycloak.js, server return HTTP 500 instead of 400.
But in keycloak-js, updateToken call ‘login’ when receiving HTTP 400 after call to ‘protocol/openid-connect/token’ with and invalid refresh_token (token is not expired, but the session state is an older one)