I'm having the same repeated problem with the RUT240 routers. The situation is that, when I insert the SIM card, they get coverage, register in the network, but never connect:
I tried to establish the connection, configuring manually the APN, but it didn't work out. It has happened to me in 4 out of 18 devices I have. I also tried to change the antennas and SIM with one that works, but with the same result. The problem isn't the SIM or the antennas. In Network - Interfaces, the MOB1S1A1 appears as Stopped, but it's enabled in the Failover and On in Interfaces.
The Serial Numbers of the devices not working are:
I don't have the last one.
Firmware version: RUT2_R_00.07.01.x, where x is 1, 2 or 4 depending on the router.
It is not a matter of time, because I left them two days trying to connect, and they still didn't connect.