The code attached below shows a simple bug in the if condition. I verified this when I wanted to use the null space capability during manipulability maximisation. For this to work, I had to set the kq joint limit avoidance value to non-zero. It should be λm instead of λΣ in one of the if conditions.

# Calculate the null-space motion if λΣ > 0 or λΣ > 0: null_space = np.eye(ets.n) - np.linalg.pinv(J) @ J qnull = null_space @ qnull_grad

The verification by setting the kq to include null space calculation worked. Can you please update this simple fix?

The exact code can be found in the this docs file in the _calc_qnull method.