ISP network monitoring

I don't know unifi networks specifically, but if your border firewall allows external ping on the WAN interface, you can setup an external ping in LM as a way to check for working internet: https://www.logicmonitor.com/support/adding-a-ping-check#PingCheck-CreatingExternalPingChecks

You can also setup the opposite and have your collector ping something(s) on the internet to check if you have internet.