Nighthawk M2 can't connect to international network even with roaming enabled

Hello,

I'm trying to use my Nighthawk M2 abroad, I turned the international roaming from the router's administration page, it shows a local network but I can't connect to it (it says "Mobile broadband disconnected").

Also the cellular network is shown as 3G whereas 4G is available (my mobile phone finds it without any issue for the same provider).

Is there any other configuration to perform to be able to use the device abroad with a foreign network provider?