TP-Link Deco Integration Broken On 2026.3.4

I upgraded HA to 2026.3.4 recently and the TP-Link Deco integration broke.

It appears to still connect to to the main Deco (I have 3x M5), find the other units, and gets a list of connected clients, but no further data and the client statuses are all listed as “Unavailable”. I tried deleting and reinstalling the integration, restarting HA, etc., with no change in behaviour.

Looking at the logs in HA there are a lot of 500 API errors relating to it.

Rolling back my docker container to 2026.3.3 resolves the issue, so something’s changed in this release that is causing the issue.

I note, sadly, that the integration is no longer updated by the owner (it’s flagged as in Maintenance Mode). Hopefully someone else will pick it up. I’ve raised a Github Issue.

HA itself is also throwing these errors:

File "/config/custom_components/tplink_deco/coordinator.py", line 49, in async_call_and_propagate_config_error
    return await func(*args)
           ^^^^^^^^^^^^^^^^^
  File "/config/custom_components/tplink_deco/api.py", line 218, in async_list_clients
    return await self._async_call_with_retry(self._async_list_clients, deco_mac)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/config/custom_components/tplink_deco/api.py", line 541, in _async_call_with_retry
    return await func(*args)
           ^^^^^^^^^^^^^^^^^
  File "/config/custom_components/tplink_deco/api.py", line 225, in _async_list_clients
    response_json = await self._async_post(
                    ^^^^^^^^^^^^^^^^^^^^^^^
    ...<4 lines>...
    )
    ^
  File "/config/custom_components/tplink_deco/api.py", line 456, in _async_post
    raise err
  File "/config/custom_components/tplink_deco/api.py", line 413, in _async_post
    response.raise_for_status()
    ~~~~~~~~~~~~~~~~~~~~~~~~~^^
  File "/usr/local/lib/python3.14/site-packages/aiohttp/client_reqrep.py", line 636, in raise_for_status
    raise ClientResponseError(
    ...<5 lines>...
    )
aiohttp.client_exceptions.ClientResponseError: 500, message='Internal Server Error', url='https://192.168.1.110/cgi-bin/luci/;stok=71e36e09e65d86be1055c39adde9aa3b/admin/client?form=client_list'

The APs regularly seem to return HTTP 500 status errors for the web UI, but HA 2026.3.3 seemed to handle them more gracefully.

Looking at it a little more closely: the client_list request is sporadically successful, but when it fails (and gets a 500) the clients are all marked as “Unavailable”. This results in clients flip-flopping between a status of “Home” and “Unavailable”.

This is observed behaviour on HA 20206.3.4, on 2026.3.3 it’s not so eagre to mark them as unavailable. I guess it backs off and retries?

Never mind, it seems related to this bug:

And a reboot of my Decos solved the immediate problem. Hopefully the PR is accepted and this is fixed.

It doesn’t seem to have been a problem specific to 2026.3.4 after all, it just manifested for me coincidentally.

Hi

I have a TP Link KH100 Hub and indeed after the upgrade to HA 2026.3.4, the integration to my Smart Radiator Thermostats stopped working, which means also my central heating integration.

What do you mean by “reboot of my Decos”?

I restarted the KH100 but it didn’t help.

The rolled back fixed the problem.

Hopefully the integration gets quickly fixed.