Strange Issue causes lights to flicker when fan control is lowered

[railgeek]

I recently bought two Lumea Controls to replace an old fan control and light control switch in a house with older wiring. I previously had a SPST switch that had all power for the fan and light wired through it. When turning this switch on, the light came on and the fan then had power. There was also a variable fan speed control in the old setup. A new ceiling fan was installed and this all seemed to work for the new fan like the old fan. However the power switch was starting to fail, and I could not find a replacement that would fit in the panel that was installed. (It is a single switch, with a horizontal orientation.) So I went with replacing everything.
The fan control is a Lumea 3-sp slide switch, model LEFSQ-FH. This is not a variable control, but has three speed settings.
The light control was a Lumea LED Dimmer, model LECL-153PH.
I rewired the outlet box to match the recommended instructions, supplying power individually to each switch by wiring the black feed wire to each black input on each switch. I have two wires to the ceiling fan, one for the fan power and one for the light power. I attached one to the red wire on each applicable control. I capped the red/white wire on both controllers.
I changed the LEDs in the light to new dimmable ones. I set the pull chain switch for the fan speed to max and turned on the pull chain light switch on the fan light as well.
The dimmer works flawlessly and will control and dim the lights without flickering.
The problem that I have is when I change speeds on the FAN wall switch from anything but high, this causes the lights to flicker. Again the light dimmer works great without flicker, and the flicker only comes into play when I attempt to set the fan control to anything but high on the wall.
This is two wire wiring without any ground leads, so green leads were tied together between controls but have no ground to be connected to.
We are currently using the fan speed settings on the pull chain for the fan, which also does not cause flicker. However, this defeats having the control on the wall and we might as well have a single switch for the fan as that is the purpose it currently serves.
Have I a wiring issue, or a bad fan controller? Should I isolate the ground leads or will that make a difference?
Thanks for any assistance that can be provided.

[Kenneth P.]

Hello, it sounds like the fan control may not be compatible with your fan. Do you have the manufacturer and model of your fan that you can use to look up and check the specs? If so, check to see if there is any information on compatible wall controls and whether this fan requires solid-state fan speed controls. If it does, we would recommend instead one of our fully-variable fan-speed controllers instead like the Skylark SFS-5E. Also to confirm, the fan load and the light load are controlled by two different controls and one does not control the other at all?