Insteon integration problem

Hi,
I did a lot of research and learned a lot since I started to look at Home-Assistant. My house is 25 years old and I build it with a domotic system at the epoc. My devices are mostly X10 and Insteon switches and dimmers.

I have a PLM 2413U connected to a Raspberry 4B and I am running a full updated Hassio.

At first, I tried the integrated Insteon support and configured some of the X10 switch and dimmers. Once, I tried to turn off and on some lights and the lights was responding with long delays and very inconstancy. The next day, I updated the Supervisor and the Host system to the latest versions and since then, I am getting no response from Insteon.

I then tried the insteon-mqtt add-on, to see if I would have more success. I am using mqtt with a temperature sensor and a board relay.

It seems that the insteon-mqtt has problem communicating with the PLM, getting the following in log:

2020-02-17 13:02:35 INFO Mqtt: MQTT message insteon/command/modem b'{ "cmd" : "refresh", "force" : true}'
2020-02-17 13:02:35 UI Mqtt: Commanding Modem device 23.9c.25 (modem) cmd=refresh
2020-02-17 13:02:35 INFO Modem: Modem sending get first db record command
2020-02-17 13:02:35 INFO Protocol: Write message to modem: All link get first
2020-02-17 13:02:35 DEBUG Protocol: Write bytes to modem: b'\x02i'
2020-02-17 13:02:35 DEBUG Serial: Wrote 2 bytes to serial /dev/ttyUSB0
2020-02-17 13:02:41 WARNING Base: Handler timed out - no more retries (0 sent)
2020-02-17 13:02:41 ERROR Mqtt: Command timed out

I tested the PLM on my Windows PC using the HouseLinc application and it is working fine. I was able to pair all my devices.

I looked at the serial port using SSH and it is ttyUSB0.

Here is a part of my config.yaml for the insteon-mqtt

logging:
  # 10=DEBUG, 20=INFO, 30=WARNING, 40=ERROR
  level: 10

  # Print messages to the screen.
  #screen: False

  # Print messages to a file.
  #file: /var/log/insteon_mqtt.log

#==========================================================================
#
# Insteon configuration
#
#==========================================================================
insteon:
  # Serial device:
  # USB PLM modem
  port: '/dev/ttyUSB0' #'/dev/serial/by-id/usb-FTDI_FT232R_USB_UART_A901M90K-if00-port0' #
  #baudrate: 9600

  # Network socket:
  # Insteon HUB PLM network
  #port: 'socket://192.168.1.5:9761'

  # PLM modem Insteon hex address
  address: 23.9C.25

  # Device database file storage location.
  #storage: '/var/lib/insteon-mqtt'
  storage: 'data'

  # Automatically refresh device states and databases (if needed) at
  # startup.  This may be slow depending on the number of devices.
  startup_refresh: False

  #------------------------------------------------------------------------
  # Devices require the Insteon hex address and an optional name. Note
  # that MQTT address topics are always the lower case hex address or
  # the input name depending on how they are configured below.
  devices:
    # On/off switch devices (outlets, wall switches, appliance modules, etc).
    switch:
      - 2F.97.FE: 'Porte Cote'
      #- 26.48.ff: 'xmas stairs'
      #- 37.2d.20: 'deck'

    # Dimming devices (outlets, wall switches, lamp modules, etc).
    dimmer:
      - 29.BF.9B: 'Balcon arriere'
      #- 48.3d.46
      #- 48.b0.ad: 'dim1'

Do I need to specify the baudrate?
There existing an add-on to use as terminal to send command to the PLM via the serial port?

Anyone can give me some troubleshooting tips?

Based on the error message posted, it looks like it cannot find the PLM. Are you sure the USB port is still /dev/ttyUSB0 after the Supervisor and Host upgrades? I know you said you looked at the port and see it as ttyUSB0 but since you are having issues with both the built-in Insteon solution and insteon-mqtt, it would seem likely that the issue is the use of the port. I cannot speak to the command line options with insteon-mqtt but if you run the following command with the insteonplm module installed you will be able to test your connection:
insteonplm_monitor --device /dev/ttyUSB0
If this command runs correctly you will see the devices load up and you will see the following

Running monitor mode
Connecting to Insteon Modem at /dev/ttyUSB0
Connection made to Insteon Modem at /dev/ttyUSB0