Hmm, I can't say for sure what that is. Is that a rhythm you're trying to play/sing that's coming out like that, or is that sound present even if you're not doing anything? Do you get that sound under the audio (guitar/voice) or instead of the audio? How loud is it? If you have the input gain cranked up very high, maybe it could be noise from computer circuitry leaking into the audio..?
The next steps I'd take in troubleshooting would be..
- Check all levels & settings, and (audio) connections on the Scarlett
- Try a different (higher quality?) USB cable
- Check that the SampleRate set in the DAW and the SampleRate set on the Scarlett Solo are the same, and that the Clock Source is set to Internal (in the Focusrite Control software)
- Check that you have the correct/compatible version of the driver (& Focusrite Control software) and try reinstalling it
- Try to record without the Scarlett interface or with a different interface (to rule out or rule in the Scarlett)
I'd assume the "Direct Monitor" button on the Solo monitors the incoming audio signal in the analog domain before it's digitized—if that's the case it wouldn't rule out the Solo as the cause of the problem, it would just point to the issue being either in or after the Solo's AD converters, the connection between the Solo and the computer, or if it's not a hardware issue with the box I'd suspect the Focusrite driver would be the most likely culprit..
A quick search suggests that there's no shortage of issues with various Focusrite interfaces regarding noise & "static". No definitive solutions offered, but various suggestions include toggling the Buffer setting, re-plugging the interface, swapping cables, and reinstalling the driver.