Sonoff S60ZBTPF Overload protection state arrives as JSON string in Home Assistant Sensor

What happened?

The Sonoff plugs send the following data for overload_protection:

 "overload_protection": {
    "enable_max_voltage": "DISABLE",
    "enable_min_current": "DISABLE",
    "enable_min_power": "DISABLE",
    "enable_min_voltage": "DISABLE",
    "max_current": 0,
    "max_power": 0,
    "max_voltage": 0,
    "min_current": 0,
    "min_power": 0,
    "min_voltage": 0
},

This data is set as this exact string to the "Overload protection" sensor of the entity in Home Assistant and I guess they should rather be separate things.

What did you expect to happen?

No response

How to reproduce it (minimal and precise)

No response

Zigbee2MQTT version

2.13.0

Adapter firmware version

0x00124b003413a9d1 Revision 20240705

Adapter

SMLIGHT SLZB-MR4U

Setup

z2m running on an x86-64 proxmox box in a lxc container

Linux zigbee2mqtt 7.0.14-14-pve #1 SMP PREEMPT_DYNAMIC PMX 7.0.14-14 (2026-08-22T15:01Z) x86_64 GNU/Linux
Debian GNU/Linux 13

Device database.db entry

No response

Debug log

No response

Notes

No response

Start by locating the Sonoff S60ZBTPF device definition and the code that maps its overload_protection data into Home Assistant sensors. Confirm how the nested object is currently serialized and how similar device state is exposed. Done means the overload protection data is no longer presented as one JSON string and the relevant behavior is covered by an appropriate test.