Double echo Aero Tracker with SkyDemon

I have tested the new Aero Tracker with Safesky and a double echo appears, but only in SkyDemon and only with the Aero Tracker. Any thoughts how to solve it?

Thank you in advance for your inputs!

Sometimes caused by misconfigured FLARM, if aircraft transmitting Mode S as well. Can you post a screenshot?

Actually, I found the answer. —> SkyDemon was not properly configured. The transponder hex code has to be entered in SkyDemon for each plane (like Safesky).