Can't get my Logitech z150 speakers to work with my XPS 8950

Hi folks

I'm just setting up my XPS 8950 for the first time. All is fine but my speakers aren't working and am wondering what I've missed.

I know they work because I just tried them with my laptop (also running W11).  Unless there's something wrong with the jack (the green one - and i've tried all six of them), then I doubt it's anything internal as my XBox headset connects by Bluetooth fine.

I have the Realtek Audio driver installed but the speakers still won't work.

I can see from Device Manager that the speakers are listed and is listed to be working properly.

I have tried running the trouble shooter (enhancements are turned off - and I have run the speakers down to 16 bit) but still nothing.  I see that the system seems to want me to use "Audio Endpoint" rather than the Realtek driver - is there a way around that so I can see if that might be prob?

Or can anyone think of something I might have missed?   All help greatly appreciated...

ta

Neil