I have created a chatbot conversation flow using the "Branch by Visitor Data" blocks. However, the conditions "If Name exists" and "If Email exists" always evaluate as true, even when I initiate a conversation from an incognito window and no name and email are passed during the chat initialization. 

Additionally, in some cases, customer names are prefilled with a UUID string.

This chat is running on top a Shopify store and no matter if a customer is logged in or not, the message in green is aways presented.

How can I avoid that issue?