I run HA OS on a Pi4 and have had issues playing audio through the 3.5mm jack using VLC-Telnet.
Found the below post and installed the MPD add-on and it just works.
https://community.home-assistant.io/t/how-to-play-sound-files-as-alarms-and-notifications-via-raspberry-pi-4-audio-socket/434282/17
Only issue I have is a notification when it plays a file:
Login attempt or request with invalid authentication
I have not found a solution for it yet, but apparently it is just the add-on trying to access album art and other data.