@Dumacos in that case I have no idea. I have several HS110 Hardware version 2.0 / Firmware version 1.5.4 myself, that shouldn’t be a problem. I have just taken a brand new HS110 and included it without issues, it immediately showed power usage data.
Running the app from the cli (see [HOW TO] CLI install method) will give more output that might help pinpointing the issue. You can also try to use one of the many other tools/scripts to connect to the plug to see if you can figure out what’s going wrong.
