The landlord does not need to consider the answers on the first and third floors. The cycle is broken, one is a virus and the other is a conflict. Now that you have ruled out the virus, I think it is a conflict or a driver or BIOS version problem, or a problem with your hardware. It can be tested for a while. If updating the BIOS and network card driver still doesn't work, don't waste time. During the warranty period, please call customer service as soon as possible, which may be a problem that you can't solve yourself.