Many ETC dimmers have configurable options which are optimal for LEDs. Whenever switching a circuit over to LED, check and adjust all of these options available.
Voltage Regulation / Regulation (Sensor+, Sensor3, Unison DRd)
This setting should always be set to Off or Disabled for circuits with LEDs. Voltage regulation will adjust dimmer output to keep voltage from changing, but the way it does that actually confuses LEDs and can make them flash erratically or dim poorly.
DC Output Prevent / Transformer Mode (Sensor+, Sensor3, Unison DRd)
This setting should always be set to On or Enabled for circuits with LEDs. Like with voltage regulation, this prevents some scenarios where dimmer output changes and can confuse LEDs.
Min Scale (Sensor+, Sensor3, Unison DRd)
This setting changes the amount of power output on the circuit when control is at 1%. This is especially useful if your LEDs are only turning on when reaching high dimmed intensity, meaning the lights will turn on instantly and have a larger dimmable range. The exact setting will depend on the LEDs in question, so some experimentation can be necessary for best performance.
LED Smoothing Mode (Sensor3, Unison DRd)
This setting can make some LEDs dim more smoothly, with little to no drawback. This should be enabled if your dimming system allows it.