USB input recognised but no signal

I’m trying to record in Audacity using a digital piano and a PreSonus AudioBox iOne.

The piano is connected to the AudioBox via a 1/4" jack, and the AudioBox then plugged into my laptop via USB.

Audacity recognises the AudioBox, and I can select it as my input in the device toolbar (https://imgur.com/a/4Fp5S2B).

However, when I try to record, I get no signal. The track stays a flat line and there’s no input sound at all. I can hear what I’m playing through the playback speakers, so the piano is playing. I know it’s an audio signal, not a midi signal. And I know it’s not a hardware problem with the AudioBox itself because I can record with it using other programs. It’s the same result whether I use stereo or mono.

Am I missing something obvious here?

Has Audacity ever recorded anything, ever?

Koz

Yep, it works fine using the same AudioBox and a microphone. It just won’t accept a signal through the instrument jack.

the same AudioBox and a microphone.

An XLR microphone? Such as what? Can you lean into the microphone and yell (never blow into a microphone), turn the Audiobox up, and get the red overload light to come on?

The instrument connecting cable is 1/4" stereo?

Or 1/4" mono (guitar cable).

The instrument is plugged into INST 2 (all the way in) and you have the “2” volume control turned up, yes?

When you tell Audacity to record in stereo, does your analog XLR microphone appear on the left?

It’s not telling me what the really big volume control does. Typically, that’s the analog out control, but I would have to look it up.

Koz

Yes. The big knob is the volume control for the “main” outputs, the two 1/4" analog connections on the back.

If you press the DIRECT button, it will mix computer playback with the live show in your headphones (overdubbing). Can you hear both the microphone and the instrument?

Koz