"/api/chat" returns a different result compared to "/api/chat/request"

[foxgem]

When a request was sent on the FastAPI swagger ui page, for the same message,

• /api/chat/request could return an expected result.
• /api/chat could not, the response was:

0:""
8:[{"type": "sources", "data": {"nodes": []}}]
0:"```"
0:"```\nThought: The current language of the user is: English. I need to"
0:" use a tool to help me answer the question.\nAction: query_index"
0:"\nAction Input: {\"input\": \"standards for letters\"}\n```\n"

After checking the output on the console, I found it was actually the same as the first part of the log messages from /api/chat/request. The following was the log when calling /api/chat/request:

> Running step 449a2807-75b9-4da4-9298-603a6341a9d7. Step input: What standards for letters exist?
Thought: The current language of the user is: English. I need to use a tool to help me answer the question.
Action: query_index
Action Input: {'input': 'standards for letters'}
Observation: The standards for letters include a weight limit of 70 pounds and a combined length and girth limit of 108 inches. Lower size or weight standards may apply to mail addressed to certain APOs and FPOs, and for Department of State mail.

> Running step 305ba39f-8366-4798-aaab-1690bef5bfb9. Step input: None
Thought: I can answer without using any more tools. I'll use the user's language to answer
Answer: Standards for letters include a weight limit of 70 pounds and a combined length and girth limit of 108 inches. Lower size or weight standards may apply to mail addressed to certain APOs and FPOs, and for Department of State mail.
INFO:     127.0.0.1:55188 - "POST /api/chat/request HTTP/1.1" 200 OK
...

Looks like the streaming interface returned the earlier, not waiting for the final result of the user query?

Thanks