@stieg  Yeah well last Friday, it had been two full days with no response (while other posts that were posted after my post were getting responses). I decided that since my post got no response this must be a known issue with the HS105 plugs.   So I did a search of the forum and found other posts with this same issue....Some of them dating back to 2017.  

So, dont hold your breath that this is getting fixed anytime soon.   It is a major flaw in a product that is suppose to help in home automation.

TP-Link seems to make very nice, quality products that fail at actual implementation.

I also have the KC200 outdoor cam that is cloud based but advertises that you can also see it "live".....that they kill every 10 minutes with time outs.   So, if you want to also use the cam for surveillance purposes its near impossible.   This is on the Kasa app on a phone, screen cast from a phone, or voice cast to a chromecast.   This also makes their one and only way they support google assistant pretty useless.  

Tony?   Carl?

Has this been looked into and/or tested yet?

Okay, well I have a quantity of 6 HS105 plugs.   I have discontinued using 3 of them.  Still using 3.  Running around the house unplugging and plugging back in each plug each time the electric blinks, or we do a router reboot is a pain.    

I have noticed:  I have 2 plugs on lamps which are "off" most of the time.  For added security I put one on our garage door.  The garage door plug is set to come on at sunrise and off at sunset.  And when we happen to need to use the garage door after sunrise, we can remotely turn our garage door back on with our phone.  So, the garage door is set to "on" all day.  If the power blinks this plug comes back online set to "on" and reconnects no matter how long it takes our router to reboot.  If I do a router reset it also reconnects since it is "on" no matter how long it takes our router reboot.  

So, the above problem is only if the plugs current state is "off" and power or reset interrupts the wifi.   

For those of you that own the HS105 Version 1 (Version 1 only) and have the same problems that this thread is discussing you should just replace them.

I contacted TP-Link support on the issue discussed in the thread.  The support was great.  Very slow...but great.  I forgive it being slow due to COVID....but sometimes took a week to get a response, usually 2-4 days.  However, once they replied they did absolutely ZERO troubleshooting and took my case straight to RMA.  To me, this means that this issue is a known flaw and can not be fixed.  

Unfortunately, I did not go through with the RMA.  They were going to replace the plugs with HS105 V3 completey free.  However, TP-Link has terrible RMA policies and even though they sold me flawed products they DO NOT pay for shipping.  They also charge for advanced shipping of replacement products before returning current flawed products.

Beautiful way to stand for your own products and customers....

In the end, it was cheaper and less hassle to just buy my own replacements by a competiter brand.   Which I will now also be doing as well with my KC200 cam,  Archer router, and range extender. 

Hope this helps someone.         

Other threads with the same/similar issue:

https://community.tp-link.com/us/home/forum/topic/151719

https://community.tp-link.com/us/home/forum/topic/102395

Dating back to 2017..... 

@Miro031 Add me to the list of people who can't reconnect my HS105 V2 to Alexa. It was working fine until I had to restart my router, then the device simply stopped working in Alexa. I could successfully control it from the Kasa app, and it was recognized by the Alexa app, but when I went to turn it on or off, I would get a "Device Unresponsive" error in Alexa. No amout of resets and deleting and readding it solved the problem.

I substituted another smart switch (an Ekticity smart plug) and had no problem connecting it. This HS105 is only 30 months old and I don't see why a simple reboot of the router should render it unusable. I'd use the Ekticity plug as a replacement, but I want the ability to offset the sunrise and sunset settings via the firmware. I shouldnt hae to use IFTTT to substitute for functionality that is already built-in to the switch.

@Miro031