Buxtyy wrote If one port is DVI-I that carries both a digital and an analog signal. If you plug it into a DVI-D port, it does not carry the pins requires for an analog signal therefore its digital only.

This ^

What that means is DVI-I carries digital and analog, meaning it works with new LCD displays and old displays like a CRT monitor.

DVI-D or DVI-Digital carries only a digital signal meaning it only works with newer displays.

You will need a different adapter for DVI-D and DVI-I I assume and that could be your issue.

You could buy a DVI-D to VGA adapter which changes analog to digital or vice versa but last I checked they were pricey. I am not sure if just getting a DVI-D to VGA adapter would work but for 1 quid it's worth a shot?