Here are some troubleshooting items that may help:
1.) Replace the batteries in the camera. Blink is notoriously bad at indicating battery life, and most abnormalities occur due to poor batteries. (This is a $2 fix)
2.) Try lowering the video quality of the XT2 and sample the audio on live view. If this helps, it could be a network speed/bandwidth issue.
3.) Do a full system reboot.
a. Take the batteries out of the camera
b. Unplug the sync module
c. Unplug your router
d. Delete the app off your phone
e. Pour yourself a drink.
f. Hook everything back up and reinstall the app
Let me know if any of these work.