Had the same issues with my Aaotec Nano Dimmer, using both ST and Aeotec USB Z-Stick controller. Couldn’t find a permanent fix, but managed to make it stable to use as dimmer with my LED lights.This issue has nothing to do with the controller.
I have two of these, both dimming light fixtures that uses 4 PAR20 6W dimmable LED lamps (24w load total each); in a 2-wire installation without Neutral. When it first powers on, it tries to determine the load type, the dimming principle (Leading or Trailing) and MIN / MAX brightness sensitivity of the load.
In my case, when it starts to detect load type during first power on, and reaches from Min to Max Brightness, lights flicker for a brief while in MAX and then it retries to go from min to max two more times and then sets itself to ON/OFF mode only (no dimming capability).
Config parameter info tells me then that it was automatically set as following:
Parameter 128 = 1 (2-wire mode)
Parameter 129 = 0 (trailing edge mode dimming principle)
Parameter 130 = 1 (resistive load)
By manually setting Parameter 132 (MAX brightness) to 95, and then setting Parameter 129 to 1 (leading edge principle) in this very same order, while keeping lights ON, I was then able to dim my LED lights as I wanted (from 0-100%, limited to the MAX I set). I also manually set Parameter 131 (MIN brightness) to the lowest value setting I wanted it to reach.
In order to prevent the Dimmer from overriding my manual configuration in each power outage, I also changed Parameter 249 (Recognition Way of Load) to 0 (Never recognize the load when power on).
My second Aeotec Nano Dimmer, for some reason, only allowed me to dim lights when setting MAX brighness level to 89. Trying to increase it made it go back to ON/OFF only; forcing me to first lower this setting, changing from leading to traling dimming mode, to finally switch back to leading mode to dim again.
My lamps also worked when setting a lower MAX brightness, and then setting Dimming Principle to Trailing Edge. But Light output was greater using Leading Edge in the MAX Brighness I could set in each dimming principle before making it unstable again.
What I found so far is that due to the complex nature of how the Nano Dimmer works in 2-wire mode; and how different circuit designs exists in dimming LED lamps, it fails to properly recognize dimming vs non-dimming LED circuits and it’s best dimming principle.
I think that Aeotec should at least provide a list of tested LED lights, because without this, planning to replace them to something that actually works as intended is impossible.