Could you add screenshot from RUT950 WebUI: Status -> Network -> Mobile when your router is connected to network and screenshot from Network -> Mobile -> General?
Which exactly Huawei router you was used? What is the model of it? Could you add screenshot from Huawei where connection status is shown when the same SIM card is used?
When you was testing with RUT950 and Huawei, how your PC was connected (wifi or wired lan) to router?