[Bug]: 2026.07.2 - switch.turn_on fails for EV Charger (multi-function single-register write rejected at 0xe1)

[Recnad806]

Describe the bug

After updating to version 2026.07.2, the new switch entity for the EV Charger does not work. The inverter rejects the command with Exception Code 3 (Illegal Data Value) because the integration attempts a multi-register write instead of a single-register write on register 0xe1.

Integration Version

2026.07.2

Homeassistant core version

2026.7.4

Inverter brand

SolaX Power

Plugin used

plugin_solax.py

Serial prefix

C31103

Inverter firmware versions

DSP 1.43 ARM 1.42-1.09

Connection Method

SolaX Pocket WiFi 3

Dongle firmware

I don't know

Detailed Error Log

Logger: homeassistant.components.websocket_api.http.connection
Quelle: components/websocket_api/commands.py:334
Integration: Home Assistant WebSocket API (Dokumentation, Probleme)
Erstmals aufgetreten: 11:32:06 (6 Vorkommnisse)
Zuletzt protokolliert: 11:33:43

[139748812275392] Error during service call to switch.turn_on: SolaX-Wechselrichter: multi-function single-register write was rejected by device 1 at register 0xe1: ExceptionResponse(dev_id=1, function_code=144, exception_code=3)
[139748137728928] Error during service call to switch.turn_off: SolaX-Wechselrichter: multi-function single-register write was rejected by device 1 at register 0xe1: ExceptionResponse(dev_id=1, function_code=144, exception_code=3)

Additional context

No response

[wills106]

This should be fixed in 2026.07.3

[Recnad806]

@wills106
I can toggle the switch now, but when I switch it to "disable," it automatically flips back to "enable," and no function is executed in the inverter. However, it does work with version 2026.07.1.

Logger: homeassistant.helpers.frame
Quelle: helpers/frame.py:348
Erstmals aufgetreten: 13:43:56 (5 Vorkommnisse)
Zuletzt protokolliert: 13:43:56

Detected that custom integration 'solax_http' passes a non-string value of type float as sw_version to the device registry at custom_components/solax_http/button.py, line 28: async_add_entities(entities). This will stop working in Home Assistant 2026.12.0, please create a bug report at https://github.com/PatrikTrestik/homeassistant-solax-http/issues

[rosenrot00]

@Recnad806 how about 2026.07.4?

[Recnad806]

@wills106
It looks like it's working now. If I run into any further issues, I'll let you know. Just leave this item open for another two days; if you don't hear from me by then, you can close it.
Thanks for the work.

[Recnad806]

@wills106

So, it works. I just tested it a few times. However, the entity needs to be activated first before it can be used; otherwise, it cannot be added to the dashboard.

[Recnad806]

@rosenrot00

it works in 2026.07.4