Apologies, feel free to close this ticket. It was an issue with the PC setup (applications were using the CPU on board GPU). Now it’s working ok
I also checked the GPU temperature, found that GPU 0 is at 32 and GPU 1 is at 45 degrees. Both cores are showing signs of some activity. GPU 0 is having pulses of activity about every 5 to 6 seconds while GPU 1 is constant at about 3%. When doing this, I had the window extended but not fully filling the screen. In this configuration, on the title screen, the music cuts out intermittently.
Yes, that was what happened (I have to admit) - the HDMI cable was plugged into the motherboard. Also the other GPU was enabled and I disabled it as part of the fix. (I did this first and then realised there was basically no graphics, before discovering I’d plugged in the HDMI cable incorrectly)