Is your device trying to connect to the cloud version or on-premises version of cnMaestro? If this is on-premises, how are you pointing the devices to your cnMaestro server?
Internet signal is ok (earth globe green). Pings to cloud.cambiumnetworks.com from device also ok.
Curiosly I have just checked the config, and the Cambium ID and Onboarding Key where blank. I rewrote them, saved, and they looked ok, but strange enough, won't survive a reboot! After rebooting they show blank again.
If I write ID and Onboarding Key, then save, then log out, then login, the ID field remains, but the Onboarding Key shows as blank (I have tried configuring through web interface with Firefox, Chrome and Edge with the same results).