Why do LED Lights Flicker on Low Dimmer Setting
LEDs on AC Power Don't Like to be Dimmed. Period.
(LEDs on DC can actually be dimmed quite easily - just look at an older battery powered LED device (like handheld computer games from the 1980s) and you can see the LEDs dim when the battery is low.)
But most AC powered LED lights - whether complete fixtures or Edison bulb incandescent replacements - have a driver circuit that takes high voltage AC and turns it into low voltage DC. That process does not lend itself well to dimming.
A modern dimmer is not, contrary to popular belief (including what I thought when I was a kid) simply reducing the constant amount of current or voltage. Rather, it chops up the power into little pieces and only sends some of those pieces to the lights.
With incandescent lights, only the total power really matters much. It also helps that the incandescent lights use the power &quot;as is&quot;, where an LED light has to convert from 120V AC down to very low voltage DC. So this works fine on incandescent lights.
However, CFL &amp; LED lights are, essentially &quot;on or off&quot;. So dimming becomes a lot more complicated. With LEDs in particular, it takes very little power to produce light, so you often end up in one of two situations:

Flickering - The LED gathers up enough &quot;bits of power&quot; until it has enough to produce light. Uses that power to produce light. Waits for some more power.
Dim - This is actually what you want with a dimmer. But with LEDs this can happen even with a very small trickle of current to power a timer/motion detector/etc., with the result that &quot;off&quot; is never really &quot;off&quot;.

There are technical solutions, aka &quot;dimmable compatible LEDs&quot; together with &quot;LED compatible dimmers&quot;. Essentially, the LED light has to figure out that the chopped up bits of power are not a deliberate attempt at flickering the lights but rather intended to dim the lights. But despite the best efforts, sometimes they just don't work well together. As you have found out the hard way.
If both the LED fixtures and the dimmers claim compatibility, I would start by trying a different brand of dimmer to see if that helps.