My Unifi Dream router showed the internet status as offline since it had been upgraded to Unifi OS 3.x
Per default the device tries to reach the address ping.ubnt.com which was reachable without any issues on the commandline of the device. Nevertheless i was not able to figure out why that doesn’t work. A thread on Reddit finally told me the correct solution - it is possible to change the address. And this is how::
Navigate via Geräte -> UDR -> Settings to the section Services:
Change the address of the Echo Servers to a public, highly available address (e.g.. 1.1.1.1 or 8.8.8.8 or 8.8.4.4)
Save and the internet status should go back to green:
