I have a MX-65 and MX-100 giving me same issue and I am not sure if it is Aircard or by design. Both of them have an active connection in WAN1 and WAN2. Also they both have cellular fail over. But Cellular is showing "connecting" at all times. Suspicion is it might be due to having two Active WAN ports. Neither one of these sites are easy to get to. Is there any way to determine if A. Aircards are bad/not connecting. or B. Meraki leaves them in connecting state while it already has two connections.The USB aircards are pretty standard and we use the same ones at other sites without issue, but they all only have one WAN connection.
'Connecting' is a pretty common thing we see with our MiFi 620 modems. For us, it generally means the signal strength to the carrier is sub-par, or simply not available. We've tried external antennae, but the RF loss is too great and it simply doesn't work. If it's possible to try a different modem with a different carrier, that may be your best bet.