Unable to connect via modbustcp to ORNO WE-571 via Protoss PW11

I’m trying to connect to a ORNO WE-571 three-phase meter via protoss PW11 wifi modbus tcp adapter.
homeassistant config is:

  - name: "PW11"
    close_comm_on_error: true
    retry_on_empty: false
    retries: 3
    delay: 1
    message_wait_milliseconds: 250
    timeout: 5
    type: tcp
    host: 192.168.100.xxx
    port: 8899
       - name: "Voltage L1"
         slave: 255
         address: 304
         data_type: float32
         precision: 1
         unit_of_measurement: V

It looks like the PW11 connects to we-517 but in homeassistant logs I get

2023-08-23 16:49:10.465 DEBUG (SyncWorker_1) [pymodbus.logging] Connection to Modbus server established. Socket ('192.168.100.xxx', 43006)
2023-08-23 16:49:10.465 DEBUG (SyncWorker_1) [pymodbus.logging] Current transaction state - TRANSACTION_COMPLETE
2023-08-23 16:49:10.465 DEBUG (SyncWorker_1) [pymodbus.logging] Running transaction 340
2023-08-23 16:49:10.466 DEBUG (SyncWorker_1) [pymodbus.logging] SEND: 0x1 0x54 0x0 0x0 0x0 0x6 0xff 0x3 0x1 0x3a 0x0 0x2
2023-08-23 16:49:10.466 DEBUG (SyncWorker_1) [pymodbus.logging] New Transaction state "SENDING"
2023-08-23 16:49:10.466 DEBUG (SyncWorker_1) [pymodbus.logging] Changing transaction state from "SENDING" to "WAITING FOR REPLY"
2023-08-23 16:49:15.471 DEBUG (SyncWorker_1) [pymodbus.logging] No response received to unbounded read !!!!
2023-08-23 16:49:15.471 DEBUG (SyncWorker_1) [pymodbus.logging] Changing transaction state from "WAITING FOR REPLY" to "PROCESSING REPLY"
2023-08-23 16:49:15.471 DEBUG (SyncWorker_1) [pymodbus.logging] RECV: 
2023-08-23 16:49:15.471 DEBUG (SyncWorker_1) [pymodbus.logging] Processing: 
2023-08-23 16:49:15.472 DEBUG (SyncWorker_1) [pymodbus.logging] Getting transaction 340
2023-08-23 16:49:15.472 DEBUG (SyncWorker_1) [pymodbus.logging] Changing transaction state from "PROCESSING REPLY" to "TRANSACTION_COMPLETE"
2023-08-23 16:49:15.472 DEBUG (SyncWorker_1) [homeassistant.components.modbus.modbus] Pymodbus: PW11: Modbus Error: [Input/Output] No Response received from the remote slave/Unable to decode response

Factory config of WE-517 didn’t change: 9600 8 1 even
Any suggestion here ?

Does anyone know how to answer this? I’m also interested in a Growatt SPH inversor.

Protoss PW11 is a converter RS484 to modbus quite cheap and I think it has a lot of people.