Yes, I’m using a 3rd-party antenna. Basically the device is mounted inside of a residential generator unit that has a metal case, so it needs an external antenna to be able to connect to the cell network.
I’m using a Taoglas U.FL to SMA connector, a 4’ SMA extension cable, and a Taoglas 2G/3G/4G external antenna. This setup works in a number of other setups, this is the first location where it has exhibited this issue.
I’m using the most recent firmware and board revisions, but using 1.6.9 of the Arduino IDE.