I installed 2 KS205 smart switches. I added the first to home assistant via tplink integration. I tried to add the second but it wanted my tplink credentials. I gave them the credentials and I got error saying they were not right. Repeated tried and failed.  Changed my password on tplink, and new password repeated failed as well deleted the integration. And restarted it, and then both switches failed to work. 
ended up trying the matter integration, the second switch worked fine but the first would just time out. Taped my phone next to the switch and waited two ministers for it to self discover, which it finally did.