Network storage gives authSIG error playing media from share - Bluesound issue?

I have my media files stored on a ProxMox folder and have set up a samba share for them. The new HA feature for network storage makes it easy to set up the storage for the share and all looks good with all of the media files and folders visible in the Media Browser.
I am using a network connected NAD amplifier as the media player and it all works well as long as I do my track or album selection on the phone app for the NAD. I can step on to the next track ok in the media player card but I cannot select a track to play in the Media Browser. If I do that the current track will stop playing and the phone app reports

Bad Request <ipaddress of HA>/media/local/MediaShare/<path to the music track>?authSig

where MediaShare is the name of the share in Network Storage.
Has anyone else encountered this? The “authSig” appears to suggest a permissions or access issue but all the things I have tried does not fix the issue.

In Notiifcations I get
Login attempt or request with invalid authentication from ( See the log for details.
where that ip address is the networked NAD amplifier using Bluesound integration. I cannot work out where the authorisation is failing as username and pwd have been set up at each point.

What is weird is that the media player card has control of volume ok and can step on to the next track or previous track without any authorisation issue (I think through a recently played list of tracks) and yet the track cannot be selected through the media browser through the media player card.
It appears to be a bug in the Bluesound integration. Anyone have any thoughts on this?

Anyone have any thoughts?

I have this same issue with a Denon AVR, but the authSig query parameter does have a value (but seems to be incomplete).

See HEOS integration unable to play local mp3 files - authentication error persists · Issue #107442 · home-assistant/core ( for why it doesn’t work on HEOS.