It seems like Drone 2.0 fails to get its external address and instead uses a blank string. This is visible in the user profile or the badge strings:
Set the DRONE_SERVER_HOST environment variable?
Indeed I have:
In fact, I did not change anything from the Drone 1 install which “knew” its own address just fine.
This was previously fixed, so please be sure to pull the latest docker image if you are still experiencing this issue.