Why doesn't the usb modem + router link work (D-Link DIR-620S + Huawei e3272)?

Question

WiFi

Hello! There is a dir-620 revision A1, with firmware 3.0.5 and a Huawei e3272 modem stitched in Hilink. The bundle started right away, but there is a problem. With one device connected, the Internet works fine, but as soon as you connect a second device via WiFi, the pages stop loading. Ping passes on all devices, though with a huge delay. I would be very grateful for your help in solving this problem.

Pings before connecting a second device

Pings after connecting a second device

Answer 1

The two most popular scenarios are:

1. The usb modem is connected via a usb cable and there is a lack of power, which is consumed both by WiFi, and by the modem, and by power losses in the cable (it happens without a cable on cheap routers, since 4G modems require quite tangible power)
   
2. Usb connected directly to the device - WiFi and modem interfere with each other, the effect is similar to problems with mobile Internet or wifi due to a cheap microwave turned on nearby
   

It is most correct to use an active self-powered usb extension cable