The variable name is reserved and cannot be used

Using the AI Chatbot builder, I can no longer create a form using the system variables. For example, if I attempt to save the user’s name as {contact_name} I’m met with a warning that says “The variable name is reserved and cannot be used“ — since contact_name can’t be used, I’m using a custom variable “user_name” — the problem is, while this value can be stored in “contacts” it does not populate in the system’s “conversations” — all conversation user names are now “Anonymous User”