I Have a Surf OTG with a MIFI Novatel U620L that stopped working. I changed the modem to Verizon Novatel USB730L it still won’t work. It attempts to authenticate then disconnects. Also when I tried to log into the Surf OTG I received a message that the certificate has expired on December 14, 2016 and I was not allowed to get into the interface, After using Avast browser I was able to get into the interface. I was running firmware 1.0.27 at that time. I upgraded the firmware to the latest 1.0.30. still unable to connect. I sent in a ticket and have not received an answer back Ticket #780752.
Thanks for your help.