Hello Drew,
Per our conversation, you have a significant number of devices within your eCatcher account that are becoming offline at the same time. THese devices are mostly Ethernet, and some cell connections to access the internet. We did have some server issues last week, but have since been restored.
For the Cellular Units: I would verify the accounts are still active and they are recieving a stable cellular reception.
I will have to check with my team is there are any server issues that would know knock out accounts.
In the meantime, here is the firewall settings as stated in our phonecall.
I would use the above document to test networks to ensure the individual units can communicate with the servers, as well as your network for access.