Thanks for your help with this issue. However, it appears the problem comes from the firmware version of my devices: version 3.02 is only compatible with the Danfoss Link, according to this post (among others): forum.fibaro.com/viewtopic.php?p=5971
So I'm currently trying to exchange them or get my money back. Obviously, I won't be able to return my two PC controllers which I have bought from another reseller.
So for anyone reading this, be cautious as these Danfoss devices have the same reference (014G0002) as other devices that are working correctly, but the firmware version makes them compatible ONLY with the Danfoss Link (wall controller, not controllable from a PC). At least that's what I've learned so far.