@Declan Yes, since the Internet IP address on the MR6400 is a private IP address, it means there is another NAT product in the front, it should be on your ISP side in your case. You could try...

@Ater In order to protect the MiFI product, it is not allowed to connect to charger and use the internet after removing the battery.

@Potpot Please check if the Internet IP on the M7350 is a public IP address or private IP address. You could also try to insert the same SIM Card into your phone and enable hotspot, then check if you...

@Stupot1264 Normally as long as your main router works fine and no settings to block devices, the MR3020 should be able to connect to the router wirelessly as a repeater. If you failed to connect it...

@obaida Hardware damaged? how did it happen? It is recommended to contact local technical support or the retailer where you bought it to check if it is still under warranty.

@MiPorto How about trying to factory reset it? Please try to recharge it to make sure the power of battery is enough