IOT card will be disconnected after monitoring on 10.30 at night.

It is a router setting problem that controls other connected devices. You can check whether other friends who use Unicom number will have the same situation as you. If the friends are normal, it means that there is nothing wrong with Unicom's network, which may be the setting of the Internet of Things card or mobile phone terminal.

Another situation is that the route is set and the traffic is also set. If the traffic is too large, the network will automatically disconnect. You can check the settings yourself or call the customer service hotline to solve it.