I get the same output and results as traboulsizs and am also running Hassio, in my case on a Raspberry pi 3 B.

I can't find any output in any log that discovery is actually starting, even though I set discovery: true. I also tried a never used Flic 1 and it's also not getting picked up. Maybe this is a problem in Home Assistant?

Can I run simpleclient on another computer and connect to flicd on the Hassio machine?