I have a simple motion tracking comp. It's an inside window frame looking out onto an outside garden. The window frame is moving in the shot, and I want the keyed BG image to move along with it, in position and scale. Not too difficult. However, when I go to Tracker 2, after Tracker 1 has run out, the BG image jumps in both X and Y axes, where it should, of course simply continue where it left off in Tracker 1. I haven't changed any parameters. When my tracking points in Tracker 1 are about to disappear, I stop the Analyze, apply the tracking info to the BG, and then start with Tracker 2 from that point.
As laid out in this thread, directly combining 2 trackers will not work for very logical reasons. Please follow the tips and tricks there for possible fixes and workarounds.