Notes not detected
Background noise is the most common cause of missed notes — a note that's audible to you but buried under competing sound may not register clearly enough for pitch detection. Moving to a quieter room usually resolves this.
Playing very quietly, especially at the low end of the keyboard where fundamentals are lower and sustain pedal resonance is stronger, can also make notes harder to detect reliably. Try a slightly firmer touch if quiet passages are consistently under-detected.
Dense chords are the current edge of what listening-based detection can separate — if a specific dense chord keeps registering as missed or wrong notes, that's a known limitation rather than a setup issue, and simplifying the voicing during practice can help isolate whether the rest of the passage is scoring correctly.