WASAPI Error Code 0 (Playback and Recording)

I used to be able to record via loopback and play it back as well using the WASAPI setting.
However, now I am getting an error code 0 on BOTH playback and recording.

It does playback and record (tho not loopback) using directsound.
And still have sound via all other programs.

Have checked the hardware device is working.
Have rescanned audio devices multiple times (inc plugging in an additional mic, to recsan to then see that but still causes an error when using the loopback option to record and then playback.

Windows 10.0.19043
Asus motherboard