@bgoyal I just went through the same thing... actually still going through it but I think I have at least somewhat of answer. I have multiple HS210's in my house and all worked great on initial install except one. I would have to click the button in the app multiple times to make it change state and it rarely showed the correct feedback state. I use Google Home and Home Assistant and all had the same response issues. 

The answer I have settled on is the light having issues has long traveler wires (wires running between switches) and a small load of LED lights only. I think the long traveler wires and small load is creating some capacitance on the travelers giving the controller in the switch fits about it's current sensing. I tested this theory by placing a resistor across the traveler wires on the switch to short the capacitance. Success. the switch then operated and reported correctly. The problem was I only had a 1/8th Watt 10K ohm resistor on hand and when the lights were off it bled too much current to the dead leg and burned the resistor up when the light was off for more than a few minutes. 

For the short term I unhooked one of the traveler wires on the smart switch and capped it with a wire nut. I then switched the dumb (standard) 3-way switch until the light turned on. Now the smart switch works and reports correctly. The other switches in the circuit cant be used now or the circuit won't work but at least the smart switch works.

The more permanent fix is getting a larger resistor to place parallel across the travelers that will limit the current draw or to add some kind of big inductive load (tungsten bulbs) to the circuit. I'm going to try a 1 MegaOhm and see what happens. I can't or don't want to change my lights as they are built in LED can lights.

Hope this helps.

  @MikeMurphy Short story, I put a 1MegaOhm resistor across the traveler screws. Bingo Bango.

Longer story, if you read the documentation there is a distance limitation on the length of the traveler wires. Using only one switch it says something like 50-100 ft. and with a TP Link switch on both ends it is something like 100 - 300 ft. I am cheap and did not want to buy another switch. I also am an electronics nerd and had access to resistors.Your mileage may vary.

Side note: I tried a 10K Ohm 1/4 watt resistor and that got hot and fried pretty quickly when the lights were off. Need something with high enough resistance to stop lights from glowing but still allow it to bleed off the capacitance. 

  @Zoidybergur Good to know, thanks! Was the 1MegaOhm a 1/4 watt?

More information for those googling their way in here...

I happened to have a surplus HS210, so I just replaced the other switch (on just one of my 3-way circuits mentioned earlier.) Interestingly, it took about a minute for the switch status to read correctly. The traveler length in this circuit cannot possibly be greater than 50 feet--but the only loads are LED lights. Perhaps current can only flow one way in this scenario, resulting in a charge pump dynamic. The extra HS210 probably increases the dissipation to overcome this.  

 The 1M Ohm bleeder resistor (across the traveller wires) did not seem to make a difference for me.

While I don't think my traveller wires exceed the maximum length specified, I suspect they are acting as if they were. My solution is to just revert the installation on the problematic circuits.