I have just bought a TP Link M7350, it worked well for a few hours, then a message came up saying, "NO SIM CARD", so have power off and on, didn't work, removed sim card and replaced, worked again for approximately 10 mins, then same message came up again, "NO SIM CARD", repeated this about another 4 times to same result, sim card provider asked me to insert into another device (my Iphone) and its working fine, I believe something wrong with new router. Can you help?

Cheers Tom