Error with playing plex content on sonos

Two days ago I successfully started playing plex content on my sonos via a home assistant automation (triggered by tag reader). This worked fine all yesterday evening to the best of my knowledge (no complaints from children). However today I’m getting the following error in the logs

Logger: homeassistant.components.automation.tag_test_card_1_is_scanned
Source: components/plex/services.py:141
Integration: Automation (documentation, issues)
First occurred: 7:00:25 PM (2 occurrences)
Last logged: 7:00:25 PM

Tag Test Card 1 @ Elizabeth is scanned: Error executing script. Unexpected error for call_service at pos 1: (500) internal_server_error; https://sonos.plex.tv/player/playback/playMedia?address=192-168-1-103.15f405376d5a4a84bf2b0c13d3216d97.plex.direct&commandID=2&containerKey=%2FplayQueues%2F10796%3Fown%3D1&key=None&machineIdentifier=6312ddfcf4f4892e60125ff43eb17397eabe6cf2&offset=0&port=32400&protocol=https&providerIdentifier=com.plexapp.plugins.library&token=transient-22743add-ddf4-4b8b-9243-28daa5c674b0&type=music&X-Plex-Client-Identifier=0x1c697a05b8ff&X-Plex-Target-Client-Identifier=RINCON_5CAAFDB75DB201400%3A1297902357&X-Plex-Token=YGLiPY-cpnojcyxjdw5b Internal Server Error
While executing automation automation.tag_test_card_1_elizabeth_is_scanned
Traceback (most recent call last):
  File "/usr/src/homeassistant/homeassistant/helpers/script.py", line 371, in _async_step
    await getattr(self, handler)()
  File "/usr/src/homeassistant/homeassistant/helpers/script.py", line 571, in _async_call_service_step
    await service_task
  File "/usr/src/homeassistant/homeassistant/core.py", line 1491, in async_call
    task.result()
  File "/usr/src/homeassistant/homeassistant/core.py", line 1526, in _execute_service
    await handler.job.target(service_call)
  File "/usr/src/homeassistant/homeassistant/helpers/entity_component.py", line 213, in handle_service
    await self.hass.helpers.service.entity_service_call(
  File "/usr/src/homeassistant/homeassistant/helpers/service.py", line 658, in entity_service_call
    future.result()  # pop exception if have
  File "/usr/src/homeassistant/homeassistant/helpers/entity.py", line 811, in async_request_call
    await coro
  File "/usr/src/homeassistant/homeassistant/helpers/service.py", line 695, in _handle_entity_call
    await result
  File "/usr/src/homeassistant/homeassistant/components/media_player/__init__.py", line 691, in async_play_media
    await self.hass.async_add_executor_job(
  File "/usr/local/lib/python3.9/concurrent/futures/thread.py", line 52, in run
    result = self.fn(*self.args, **self.kwargs)
  File "/usr/src/homeassistant/homeassistant/components/sonos/helpers.py", line 28, in wrapper
    return funct(*args, **kwargs)
  File "/usr/src/homeassistant/homeassistant/components/sonos/media_player.py", line 530, in play_media
    play_on_sonos(self.hass, media_type, media_id, self.name)  # type: ignore[no-untyped-call]
  File "/usr/src/homeassistant/homeassistant/components/plex/services.py", line 141, in play_on_sonos
    sonos_speaker.playMedia(media)
  File "/usr/local/lib/python3.9/site-packages/plexapi/sonos.py", line 93, in playMedia
    self.sendCommand(
  File "/usr/local/lib/python3.9/site-packages/plexapi/client.py", line 231, in sendCommand
    return query(key, headers=headers)
  File "/usr/local/lib/python3.9/site-packages/plexapi/client.py", line 192, in query
    raise BadRequest(message)
plexapi.exceptions.BadRequest: (500) internal_server_error; https://sonos.plex.tv/player/playback/playMedia?address=192-168-1-103.15f405376d5a4a84bf2b0c13d3216d97.plex.direct&commandID=2&containerKey=%2FplayQueues%2F10796%3Fown%3D1&key=None&machineIdentifier=6312ddfcf4f4892e60125ff43eb17397eabe6cf2&offset=0&port=32400&protocol=https&providerIdentifier=com.plexapp.plugins.library&token=transient-22743add-ddf4-4b8b-9243-28daa5c674b0&type=music&X-Plex-Client-Identifier=0x1c697a05b8ff&X-Plex-Target-Client-Identifier=RINCON_5CAAFDB75DB201400%3A1297902357&X-Plex-Token=YGLiPY-cpnojcyxjdw5b Internal Server Error

I get that a 500 error from the sonos.plex.tv is probably an error on the plex side of things but;

  1. Has anyone seen this problem before?
  2. Is there any way to get more information on what happened (perhaps there are more details in the http response)?

Interesting observation… yesterday when it was working remote access was enabled but not available outside my network (this is supposedly supported see “What if I Can’t Get Remote Access Working?” Requirements for using Plex for Sonos | Plex Support ). Today the same page is showing “Fully accessible outside your network”, even though it doesn’t work outside the network.

FYI if anyone gets the same error message. After manually adding a port forwarding to my router (not so happy about doing that…) everything seems to be working again.