CPA反代，偶发失败 
问题描述： 
调用 gpt-5.6-sol 模型时遇到 HTTP 502 错误，请求无法正常完成。 
错误信息： 
HTTP 502 
{
  "error": {
    "type": "server_error",
    "code": "server_error",
    "message": "An error occurred while processing your request. You can retry your request, or contact us through our help center if the error persists."
  }
}