The damage dealt by Soul Scorch initial hit on an enemy is the same regardless of whether they are afflicted with Warlock's Curse or not.
The damage dealt by the Soul Scorch radiating DoT does, correctly, deal increased damage to enemies afflicted with Warlock's Curse
https://docs.google.com/spreadsheets/d/12H-D3ezTbSvMrWBauEfmM1ZigA9hIb05rbcWeyy1vtU/edit?usp=sharing