Julian OH8STN <julian@...>
It sounds like you're running the 7300 from its internal sound card (audio codec) via the USB port, rather than from the DRAWS hat. You must connect the DRAWS hat to the 6 pin mini-din on the rear of the 7300. Then select the DRAWS hat as the audio source in fldigi, after its configuration.
Apologies if I misunderstood your configuration.