Can't "Track Forward" on with Match Motion FX

Dealing with something strange: for whatever reason I am unable to Track Forward on one specific clip when using the Match Motion FX. I am able to load the FX, and even select multiple track points, but when I hit "Track Forward," all that happens is I get a flicker of the "Track Progress" pop-up window before it disappears and I'm left with no tracking data captured.

Even stranger is I was just able to successfully execute Tracking Forward on a Match Motion FX node on a nearly identical separate clip. Same codec, same frame content, and near identical node tree grade...

I even tried deleting the node tree entirely, reseting everything, then having only one node with the Match Motion FX loaded -- and I STILL can't track forward. I can't figure it out for the life of me. Any suggestions are greatly appreciated.

Thanks!