I purchased this M2 board a while back and have been unable to get it to connect to any SIM. I've tried various SIMs from all the main 3 service providers.. these SIMs do however work in my GL-XE3000. I've searched and asked around but can't figure out what's wrong. I've tried QMI, QCM, different ports, and other fixes I found whilst searching. I'd greatly appreciate any help or guidance.