@Lei Sun On February 12, 2025, the developer support plan provided a new experience where you receive business hours access to Support Engineers on Microsoft Q&A with prioritized responses, as the first line of support.
For details on the SLAs and other benefits provided for each support plan, please see here.
Currently the new experience is only limited to Developer support plan only and for all other support plans, customers can continue to use portal as first engagement mode.
If you require assistance with a technical support issue, please post a new thread so we can assist you on providing a resolution.