We've identified an issue introduced with the Windows 10 April 2018 update, which resulted in distortion and playback issues, when Serato DJ Pro 2.0.3 or below was used in the 1 or 2-deck offline modes.
A fix for this has been implemented in Serato DJ Pro 2.0.4, which you can download below:
Note: This issue does not affect playback when Serato hardware is connected as the primary device.