Multi-Agent Node — "Include Chat History: No" not fully suppressing $chatHistory context?

Summary:

I have a Multi-Agent node (a Planning Agent delegating to a single specialist Worker agent) that resolves NetSuite account numbers to their corresponding Oracle account numbers via an exact-match lookup against a vector index.

The issue: When two related account-number questions are asked back-to-back in the same conversation session, the second question's answer appears to get incorrectly influenced by the first question's result — even though:

• The Multi-Agent node's "Include chat history" toggle is set to "No"
• A custom session-tracking variable I use elsewhere is confirmed empty at the time of the second call
• The Planning Agent's prompt explicitly instructs it to treat each question independently and disregard any prior conversation context