There are following factors that could probably make this happen:

• Too many mobile digital devices connected to the router simultaneously.——You may reduce the connected mobile terminal devices to release the router’s load limitation.

• High temperature of the router or surroundings.——Please remember to keep away from extremely high temperature environment like fires or something else.

• Excessive signal ambient interference. Avoid high frequency signal interference device like microwave oven and something else.
• The configuration of router have some problems. Like restart function.
• The faulty of the firmware/hardware devices itself. And you are supposed turn to sales return or repairing.