Step, trot, run, walk are very unstable

My beautiful Bittle from the kit is complete, and many things work as they are supposed to.

However, in the walk, run, trot and step functions, Bittle usually cannot go far, and stumbles. When I lift Bittle and do these functions in the air, the legs appear to be moving correctly. The "crawl" function does work, it can crawl around the room without issues. Sometimes, I can get it to trot for a few seconds and move a foot or two, but most other times, it collapses, flails, and flips over.

I have experimented with shifting the battery, thinking it looks like it could be a balancing issue, but that does not seem to help. It is difficult to determine at what point it is failing (maybe I should try slow motion video). It is almost as though one or more of the legs are too "weak" to support it? I connected to the computer and went through the calibration instructions again to ensure it is perfectly calibrated (as far as I can tell). I will double check this too to make sure it was all saved.

Any advice to troubleshoot?

Here is my output from calibration:

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

0, 0, 0, 0, 0, 0, 0, 0, -5, 1, -4, 1, 2, -2, -3, 2,