Dear Aamirniaz434,
I have check the issue with RD, and already get the solution. Please check the following method to solve your issue. I have test it in my side. Thanks!
1.Please use the AT+CGDCONT to set the APN for context 3, the following is the example:
2.Please use AT+CGDCONT? to check all the context setting. Please make sure the contxt 1 and 3 use the different APN and the two APN are all correct of the SIM card you used.
3. Then enable WIFI function with command AT+QWIFI=1,1,3.
4. You can use the AT+CGPADDR to check whether the context 1 and 3 already obtain IP address. Please note that only them can obtained the IP normally, then you can use WIFI and USB ethernet to access the network simultaneously.
5. After that you can try to use internet over USB and WiFi together.
Hopefully the above method can help you solve the issue. Thanks!