Open Solfio → tap "Practice more (Pro)" → "Restore purchase". Make sure you're signed into the Apple ID / Google account used for the original purchase.
Solfio plays even with the iPhone mute switch on (by design). Check your volume and that no other app has exclusive audio. On Android, check media volume, not ringer volume.
Days reset at midnight UTC. One automatic streak freeze regenerates every 7 days and silently covers a single missed day.
support@solfio.app — include your device model and OS version.