core: Sonos cannot play TTS file - "connection lost"

The problem

Sonos does not want to play files created by TTS service. I am getting “unable to play [long file name from tts].mp3 - the connection to 192.168.1.3:8123 was lost”. I am not convinced this has anything to do with Sonos but I am not sure where to go.

I have tested TTS (Microsoft) via Postman and got the file.

I can see the file in TTS folder created by service call tts.micorosoft_say and the file that was created.

I can play file in VLC by navigating in Explorer (via smb) to 192.168.1.3.

Internal site responds to https😕/192.168.1.3:8123 (with warning about the cert - Let’s encrypt expired Feb, 2020)

http😕/192.168.1.3:8123 - in a browser I get connection reset. (in postman “Error: socket hang up”)

Site is accessible via nabucasa.

All firewalls are disabled.

Environment

• Home Assistant Core release with the issue: noticed @ 0.111.2
• Last working Home Assistant Core release (if known): 0.110.4
• Operating environment (Home Assistant/Supervised/Docker/venv): Docker
• Integration causing this issue: Sonos
• Link to integration documentation on our website: https://www.home-assistant.io/integrations/sonos/

Problem-relevant configuration.yaml

Traceback/Error logs

2020-06-13 23:00:24 DEBUG (MainThread) [homeassistant.components.websocket_api.http.connection.140646918849104] Received {'type': 'call_service', 'domain': 'tts', 'service': 'microsoft_say', 'service_data': {'message': 'Mama is home', 'entity_id': 'media_player.office'}, 'id': 116}

2020-06-13 23:00:25 DEBUG (MainThread) [homeassistant.components.websocket_api.http.connection.140646918849104] Sending {'id': 116, 'type': 'result', 'success': True, 'result': {'context': Context(user_id='859cfe3238224dc6a19e5c5e3edc0579', parent_id=None, id='c186310e64524304aebf655763898a56')}}

2020-06-13 23:01:30 DEBUG (MainThread) [homeassistant.components.websocket_api.http.connection.140646918849104] Received {'type': 'call_service', 'domain': 'media_player', 'service': 'media_play_pause', 'service_data': {'entity_id': 'media_player.office'}, 'id': 117}
2020-06-13 23:01:30 DEBUG (MainThread) 

[homeassistant.components.websocket_api.http.connection.140646918849104] Sending {'id': 117, 'type': 'result', 'success': True, 'result': {'context': Context(user_id='859cfe3238224dc6a19e5c5e3edc0579', parent_id=None, id='be03ed9035934a8fa348e3d2baa17076')}}

Additional information

I tried tracing (wireshark) the call from my computer Sonos instance and could not determine how it’s trying to connect to hass instance.