如何在IIS10中运行启用WebSocket的FastAPI？

已成功在IIS 10上部署运行FastAPI，但WebSocket功能异常，客户端始终提示错误：WebSocket is already in CLOSING or CLOSED state.

当前web.config配置 #

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <system.webServer>
    <handlers>
      <add name="PythonHandler" path="*" verb="*" modules="httpPlatformHandler" resourceType="Unspecified"/>
    </handlers>
    <httpPlatform processPath="C:\Public-T\Python\VenvFastapi\Scripts\uvicorn.exe"
                  arguments="main:app --host 0.0.0.0 --port %HTTP_PLATFORM_PORT%"
                  stdoutLogEnabled="false"
                  stdoutLogFile="D:\WebSite\FastApi\logs\uvicorn"
                  startupTimeLimit="60"
                  processesPerApplication="16">
      <environmentVariables>
        <environmentVariable name="PYTHONPATH" value="D:\WebSite\FastApi\" />
        <environmentVariable name="HTTP_PLATFORM_PORT" value="%HTTP_PLATFORM_PORT%" />
      </environmentVariables>
    </httpPlatform>
  </system.webServer>
</configuration>

WebSocket代码（单独运行正常） #

@app.websocket("/ws")
async def websocket_endpoint(websocket: WebSocket):
    await websocket.accept()
    while True:
        data = await websocket.receive_text()
        await websocket.send_text(f"Message text was: {data}")

内容的提问来源于stack exchange，提问作者user2393163