@Solla-topee  I have the same problem .. main switch works but satellite is a dud and nothing works. 
 

Also the weird thing is the circle on switch is always on in both switches. Main switch works otherwise and also works via app. 
 

Any ideas would be awesome 

I know I've encountered a 2-way that wouldn't even turn on a particular fixture until I calibrated the switch's dimming range. I wonder, do the primary and secondary dimmers' ranges need to be calibrated separately?  Perhaps they ship differently because of some unintentional, initial programming/settings of the dimming range. Have you tried calibrating the ranges?

@HappyKing got this tonight .. seemed like everything was working and suddenly it turned off .. I got this message on the app when I tried to turn it back on ..

it's a simple chandilowr with 12 candelbera bulbs ..

I have another Leviton switch for a living room chandiloer that has 30 bulbs and no issues with dimmer.

I'm in the same boat. Both switches are hooked up properly, both switches have power, the main switch is flashing red.

I have the same issue as many others here. The main switch works and is able to turn on and off the lights as well as dim. The satellite switch constantly has the round LED ring on, and is able to switch the lights on, but is unable to dim the lights or turn them off. Wiring has been triple checked as per reply #4 and can confirm it is correctly wired. Please let me know if there is a solution or is it a defect satellite switch that needs to be replaced. Thanks!

I'll join the club.  KS230 not working for me either.  Primary device is working fine, but slave does not function at all.  All wiring performed by a professional electrician.  Does anyone know of a solution?  Has anyone installed a unit that is working correctly?  I could always buy another and return this one.

  @Chuckc Same here! I had version 1.0 and it worked about 20% of the time. I had it replaced with a 1.8 and now the satellite switch only turns on the lights if they are off. The dimmer switches don't work at all. Why can't they get this right? They should just let them talk over the WiFi connection instead of trying to use some low voltage signal!

I have had it with these switches... out of 7 I ordered off Amazon, only one has worked. I had hopes for the last one, but 15 minutes after connecting it, the red flashing light of death appeared. 

I'm not really interested in manually managing the firmware on these devices, so I'm returning this last one and switching brands for the 3-way switches I need in my home. 

I have been impressed with the ease of these switches since I started installing them in my house, but at this point, I'm over this particular product.

Fadam wrote

Just got the new KS230 3 Way Dimmers. I purchased 2 sets first set the secondary switch will not work. Second set the main switch will not connect to the app. No TPlink appears. Spent the whole day trying different configurations to no sucess. I have other TP Link / Kasa switches throughout with no issues.  

Has anyone had these issues.