Silicon Labs Multiprotocol addon failing intermittently causing HAP, Thread and Zigbee issues

### Describe the issue you are experiencing

Every few days to a week, the Silicon Labs Multiprotocol addon will stop communicating and indicate 'resource temporarily unavailable'. yet does not make mention of which resource this is. When this addon stops, it breaks my light integration (Nanoleaf via Thread using HAP) and Zigbee sensors via ZHA.

Restarting the addon doesn't fix the issue, nor does restarting home assistant. Usually requires a complete reboot of the host, and even then sometimes it will repeatedly indicate 'resource temporarily unavailable'.

### What type of installation are you running?

Home Assistant OS

### Which operating system are you running on?

Home Assistant Operating System

### Which add-on are you reporting an issue with?

Silicon Labs Multiprotocol

### What is the version of the add-on?

2.3.2

### Steps to reproduce the issue

Wish I knew, as it fails whenever it wants to (sometimes 3am in the morning, sometimes 5pm in the afternoon).

### System Health information

## System Information

version | core-2023.8.4
-- | --
installation_type | Home Assistant OS
dev | false
hassio | true
docker | true
user | root
virtualenv | false
python_version | 3.11.4
os_name | Linux
os_version | 6.1.37
arch | x86_64
timezone | Australia/Adelaide
config_dir | /config

Home Assistant Community Store

GitHub API | ok
-- | --
GitHub Content | ok
GitHub Web | ok
GitHub API Calls Remaining | 5000
Installed Version | 1.32.1
Stage | running
Available Repositories | 1335
Downloaded Repositories | 37

AccuWeather

can_reach_server | ok
-- | --
remaining_requests | 14

Home Assistant Cloud

logged_in | false
-- | --
can_reach_cert_server | ok
can_reach_cloud_auth | ok
can_reach_cloud | failed to load: unreachable

Home Assistant Supervisor

host_os | Home Assistant OS 11.0.dev20230705
-- | --
update_channel | beta
supervisor_version | supervisor-2023.08.3
agent_version | 1.5.1
docker_version | 23.0.6
disk_total | 30.8 GB
disk_used | 23.3 GB
healthy | true
supported | true
board | ova
supervisor_api | ok
version_api | ok
installed_addons | Samba share (10.0.2), Network UPS Tools (0.12.0), Matter Server (4.9.0), Silicon Labs Multiprotocol (2.3.2), Mosquitto broker (6.2.1), Zigbee2MQTT (1.32.2-1), Custom deps deployment (1.3.3), Home Assistant Google Drive Backup (0.111.1), ESPHome (2023.8.2), Terminal & SSH (9.7.1), Studio Code Server (5.10.1), PS5 MQTT (1.3.1), Whisper (1.0.0), Piper (1.3.2), Advanced SSH & Web Terminal (15.0.7), Silicon Labs Flasher (0.2.0)

Dashboards

dashboards | 3
-- | --
resources | 24
views | 11
mode | storage

Recorder

oldest_recorder_run | 16 August 2023 at 08:32
-- | --
current_recorder_run | 25 August 2023 at 20:34
estimated_db_size | 933.92 MiB
database_engine | sqlite
database_version | 3.41.2

### Anything in the Supervisor logs that might be useful for us?

```txt
Nothing relating to these issues.
```

### Anything in the add-on logs that might be useful for us?

```txt
Logger: bellows.zigbee.application
Source: /usr/local/lib/python3.11/site-packages/bellows/zigbee/application.py:643
First occurred: 10:49:25 (4040 occurrences)
Last logged: 17:00:02

ControllerApplication reset unsuccessful: ConnectionRefusedError(111, "Connect call failed ('172.30.32.1', 9999)")
Traceback (most recent call last):
File "/usr/local/lib/python3.11/site-packages/bellows/zigbee/application.py", line 640, in _reset_controller_loop
await self._reset_controller()
File "/usr/local/lib/python3.11/site-packages/bellows/zigbee/application.py", line 661, in _reset_controller
await self.connect()
File "/usr/local/lib/python3.11/site-packages/bellows/zigbee/application.py", line 133, in connect
self._ezsp = await bellows.ezsp.EZSP.initialize(self.config)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.11/site-packages/bellows/ezsp/__init__.py", line 164, in initialize
await ezsp.connect(use_thread=zigpy_config[conf.CONF_USE_THREAD])
File "/usr/local/lib/python3.11/site-packages/bellows/ezsp/__init__.py", line 181, in connect
self._gw = await bellows.uart.connect(self._config, self, use_thread=use_thread)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.11/site-packages/bellows/uart.py", line 414, in connect
protocol, _ = await _connect(config, application)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.11/site-packages/bellows/uart.py", line 385, in _connect
transport, protocol = await zigpy.serial.create_serial_connection(
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.11/site-packages/zigpy/serial.py", line 31, in create_serial_connection
transport, protocol = await loop.create_connection(
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.11/asyncio/base_events.py", line 1085, in create_connection
raise exceptions[0]
File "/usr/local/lib/python3.11/asyncio/base_events.py", line 1069, in create_connection
sock = await self._connect_sock(
^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.11/asyncio/base_events.py", line 973, in _connect_sock
await self.sock_connect(sock, address)
File "/usr/local/lib/python3.11/asyncio/selector_events.py", line 628, in sock_connect
return await fut
^^^^^^^^^
File "/usr/local/lib/python3.11/asyncio/selector_events.py", line 668, in _sock_connect_cb
raise OSError(err, f'Connect call failed {address}')
ConnectionRefusedError: [Errno 111] Connect call failed ('172.30.32.1', 9999)
```

### Additional information

HAOS is hosted in a VM on my Unraid server. My Unraid server is still able to see and interact with the USB device(s) when HAOS fails to. For context:

I have the SkyConnect USB as well as a Sonoff Zigbee 3.0 USB Dongle Plus V2” (model “ZBDongle-E”). I mainly use the Skyconnect for everything, and the Sonoff is a recent purchase. Both are flashed with the latest version of the MultiPAN firmware.

I have tried both the stable and beta version of HAOS, no change to the outcome. Sometimes it works for several days, sometimes it fails > 5 times a day.

Start with the Silicon Labs Multiprotocol add-on logs and the bellows/zigpy traceback, especially the connection attempt to 172.30.32.1:9999. Compare the failures with the Home Assistant OS VM and USB-device setup described; done means identifying the cause of the intermittent connection refusal and documenting a reproducible fix.

Written by the indexing model from the issue text.