Okay, fixed for next release, just needed to remove the extra cells that were jumped from their path. Surprised that's been in there for so long! (Although the fact that it only happens when there are no enemies in view, and only at certain angles, makes it less likely to be discovered...)
It wasn't happening for even larger bots because after the jump there was a disconnect in the path, so it couldn't follow and gave up. 2x2 was small enough that there was no disconnect--they were still adjacent to the next cell in the path, but it would send them in the reverse direction!