I have been wrestling with an issue for the last month and cannot seem to get it fixed. I have a ticket open with TP-Link Support but “they do not support Home Assistant”.
I see there have been many posts about this but they seem to magically fix themselves and they are a few years old and I cannot help but think that this problem is due to a change on their firmware and I have duplicated this problem successfully.
The HS300s work great until power is dropped to them and it seems as if Home Assistant cannot log into them, anymore. The EP25s I have do not have this problem, so I think it is safe to say that this is centered on the HS300 hardware.
When these drop power, these still work fine in the KASA app. I can turn things on or off without issue.
Third Party Compatibility has always been set to “On”
Home Assistant version: 2025.11.1 Core, 2025.11.2 Supervisor, Operating System 16.3 on a Raspberry PI 4B with 16GB of memory.
I have the Sense energy monitor and post power loss, these still work fine with it. In fact, its integration with Sense and Home Assistant is why I bought 28 of them.
I changed my TP-Link/Kasa Password to make sure I was using the right one and I am. When I changed it, I had to change the HS300s that had not rebooted in Home Assistant and they came back.
This started when I popped a breaker in my living room and 5 of them stopped working. I factory reset two of them and that did not fix it. The other 3 came back when I changed my TP-Link/KASA password, along with the others except these two.
Today, I popped my GFCI starting my smoker (happens for some reason, even though I replaced the GFCI and works fine after that). I lost the two that were connected to it so this does happen upon a reboot.
I even bought a new one and set it up and it all worked fine until I pulled power and then it is like everything else.
I could probably generate a network trace if someone thinks that would be beneficial. Here are the associated log messages, all indicating a bad username and password, but I am using the correct one and the same one I use on the working devices.
Logger: homeassistant.config_entries
Source: config_entries.py:789
First occurred: 12:19:01 PM (2 occurrences)
Last logged: 12:19:01 PM
- Config entry ‘Backyard PS1’ for tplink integration could not authenticate: Device authentication error connect: Device response did not match our challenge on ip 192.168.253.50, check that your e-mail and password (both case-sensitive) are correct.
- Config entry ‘Backyard PS2’ for tplink integration could not authenticate: Device authentication error connect: Device response did not match our challenge on ip 192.168.253.57, check that your e-mail and password (both case-sensitive) are correct.
For username, it is my E-Mail address, all lower case.
For my password, it contains upper and lower case letters, numbers and a special character, specifically the ! character (that’s all you are going to get out of me on my password).