Alexa ask Vocal Code even if not enabled

As stated in subject, I've successfully setup my Ring Intercom about 3 weeks ago. I've successfully connected Echo Dot with Alexa Skill and I can unlock my front gate.Last 3 days, all of a sudden, when I ask Alexa to unlock she asks me my Vocal Code. Here's my try until now:- Setup Vocal Code, ask Alexa, answer to Vocal Code and successfully unlocked my gate- Enable/Disable Vocal Code, Alexa keep asking for it- Uninstall Alexa Skill and re-installNone of this, apart from setting Vocal Code, make Alexa working as before.Thanks for any hint