It sounds like you might be dealing with a possible latency issue. Here are some things to check:
1. When exporting your .wav file, check the box in the export window for realtime processing.
2. Open the control panel for your audio interface and increase the audio buffer size, aka Device Block Size.
3. Make sure that you are not running a 5400 rpm hard drive in the system. You will want to write to a 7200 rpm hard drive or faster.
If you have any problem with these steps or would like a PreSonus tech to take a look at your system, please submit a support ticket at my.presonus.com.