Trying to install a 3 way switch on one end and a toggle on the other.  Having a major issue with the lights quickly flashing. This is not a sync type of flash. The lights flash faster and the switch itself is making a loud click each time.  I have been scavenging through help videos, forums and articles to find an answer and have yet to solve it.   I'm amazed how many articles I've found about this issue and there are basically no answers.  Kasa even seems to be unaware of this issue in a close topic I found on here with the same title (so I named this part 2.)   In that thread the solution they found was switching the Kasa and the classic switch to solve it.  Unfortunately switching those around did not work in my case.   I understand the line, load and travelers.  (Line vs Load end) which allows power to the switch.  I've been over it for hours today.  In either layout, if the toggle switch is off, the Kasa switch does this error. It either flashes or doesn't work at all.  There is no solid on light.   I installed the most recent software update, no difference. I installed another of these switches AND a single switch and have seen this issue almost every time I have installed an outlet in my house (another reason I can't believe Kasa hasn't heard of this before.)  It usually means that the wiring is incorrect and I need to find a work around.  My house apparently has a ground wire issue that these sensitive smart switches don't like?  I have always figured it out in the past, with a little work, but this time it doesn't seem to work no matter what i try.   I have literally spent 10-12 hours switching wires in every combo.   Can anyone give me an answer?