@Fadam 

Yes, I have had the same problem.  Secondary units do not work.  I have tried this with 2 different KS230 KIT sets.  The only time I did get 1 main switch from one of the sets working was with a dumb 3-way switch at the other end, but the functions of the dumb switch did not all work (could turn off the lights from the dumb 3-way switch but could not turn them back on).  And, after messing with these KS230 KIT sets for many, many, many hours trying to get them to work, now the main switches do not work.

I put the dumb 3-way switches (only 1 of them has the dimmer control) back and everything works perfectly, so I know it is not my wiring.

In another lighting area, I installed the tp-link 3-way switch set that is not dimmable with no problems... I did notice that on the setup for that set the app prompts for the main switch and then prompts for the secondary switch... that doesn't happen with the 3-way dimmable sets... the app just prompts for the main switch and then setup is done.  Also... both switches in the non-dimmable set have a neutral wire.  The secondary switch in the 3-way dimmable sets do not have a neutral wire.

@LarBear Irritates me they would release it like this, but at least I'm not going to waste anymore time trying to figure this out. I also tried to use the dummy switch as a secondary which seemed to get the master to work like you said, but thats not what I'm looking for. Might go with no dimmer for one of my setups not sure with the other one yet. Thanks for your help. 

@Fadam , @LarBear ,

The secondary switch in the 3-way dimmer does not need to be added/synced with your home automation system. Only the primary needs to be synced.  The secondary is essentially a load remote.

Unlike the 3-way switch "Kit", the 3-way dimmer actually is a kit and it must be used as a kit.  You can't use the 3-way dimming primary with a dumb 3-way switch.  I don't even think you can use it with a dumb 3-way dimmer, though I have not tried and I don't know if I'd feel saving doing so as the electronics in the primary were not intended for it.

Hi, I have exactly the same problem, and I have triple checked my wiring with multi-meter. Main unit works fine, can be controlled with phone, got the firmware update. The satellite switch always appear to be in the off-mode (white ring light on), but pressing it has no effect whatsoever. Can you please include me as well in the support case?

@Solla-topee 

Fortunately, I had a 3rd KS230 Kit and decided to try that set with the same wiring setup.  That set worked perfectly the first time!  It also received a firmware update as soon as it was powered on.

I set up an exchange with Amazon to send the 2 non-working kits back for new ones.

I'll do you all one better. After messing around after rewiring my circuit I was able to get both master and slave working. I added the master to the Kasa app performed the update and was in love with the switch for twelve hrs. When I woke up the slave switch is no longer working. The master works fine, it is in the Kasa app, both alexa and home assistant can perform their automations. The slave no longer will controll the light, its ring light is very dim and always on regardless of if the light is on or not, the ring light turns off whenever the padel or the dimmer buttons are pressed. This is very annoying problem. 

Yeah, I had the same issue. I had an electrician come out to install the switches to ensure that it was done correctly. The electrician is telling me the wiring is fine. It was reported by the electrician that both switches initially worked. I synced the switch to my Kasa app, it had me do a firmware update. The lights worked fine, worked from the app. Then found out the satellite switch did not work when I tried. He double and triple checked the wiring. Then the switches seem to now have gotten stuck in a 'boot mode', the amber WiFi indicator is on, and the 3rd white dot is illuminated on the master switch. I was in touch with technical support, it has been escalated - but now I don't know if they're planning to send me a new switch set? It would be nice to know what the amber WiFi image + 3rd white dot means and if it can be reset.

I posted a message on the board, but it seems it's either stuck in moderation or it was deleted... 

I have a HW: V1 FW:1.0.10 HS230Kit with a dead satellite (unresponsive to touch, no lights).   Master can still power on the light and control dimness through it.

The master has the 5th from the right (3rd from the left) brightness level dot illuminated at all times.

Pulling it out of the wall, it appears (using my non-contact voltage tester) that both traveler 1 and 2 are dead from the master when the master is off and both are energized when the master is on...  Or at the very most they're low voltage... I wish I had my multimeter with me to test voltages.   It would also be helpful to know what the expected voltages are across each line in on and off.