We have been seeing some strange behavior with our Nova R410 (FW ver: L0.0.00.00.05.08,A.02.04) when trying to get a PPP connection (hologram network connect) this morning (Eastern time). The modem consistently failed to get a PPP connection, with the error Modem hangup - possibly due to an unregistered SIM. This modem had been on the Hologram network in the past without issue.
We noticed Hologram was reporting SpaceBridge issues issues. Now that the issue is resolved, our modem is able to get a PPP connection. Can you confirm that troubles with SpaceBridge would likely result in trouble with a modem setting up a PPP connection? One interesting data point, during the SpaceBridge troubles, we had several 3G Novas (Sara-U201) with no trouble getting/keeping PPP connections.
Related to this PPP issue, when the hologram network connect command failed to connect the device (/dev/ttyUSB1) went away every time. Once the network connect failed, we could no longer do anything with the modem. Is there a way to prevent /dev/ttyUSB1 from going away if the network connect command fails?
Kind of sounds like you might be running into a power issue maybe causing the modem to brown out. The serial port shouldn’t normally disappear when ppp fails although it might get tied up for a minute until some processes timeout.
What kind of Raspberry Pi are you using and how are you powering it?