FFPro Clicking or Tapping When Hotend Moves in X-Axis

I've been using my FFPro since January and it's been great. I've logged about 700 hrs on it. I've recently noticed a tapping or clicking sound while printing.

I moved the carriage manually by hand, and the noise only happens when moving in the x axis. Is the belt supposed to be centered on the geared pulley or flush to one side? Right now the belt is flush to one side of pulley. If I try and move the belt to the middle of the pulley it moves itself back after a couple of passes with the carriage. I can't tell if it's the belt that making the sound, but it's definitely the pulley or something on that left bracket that is attached to pulley that's responsible for the noise. It can be reproduced by moving back and forth on the same spot in the x axis.

Other than the click noise, the prints are still are still coming out fine.
Here's a video of me manually moving the carriage:
https://www.dropbox.com/s/dt3fx5ak1s..._6586.MOV?dl=0

Since this video, I've cleaned and lubed all smooth rods with white lithium grease. Clicking sound is still coming from around the area of the grey pulley on the left hand side.

Has anyone encountered this? I've started an email thread w FF support, but I thought I'd check here in case anyone else as had the same issue.