I had re-executed the code. I don't see the dot anymore.
I had increased the limitation on filtering by putting limits on (value + uncertainity), instead of having lower limit (value-uncertainity)
passiv_cond = (eta_x + eta_u <= eta_max_x + eta_max_u) & \
(eta_max_x + eta_max_u <= 1) & \
(delta.x + delta.u <= 1)
passiv_cond = (eta_x + eta_u <= eta_max_x + eta_max_u) & \
(eta_max_x + eta_max_u <= 1) & \
(delta.x + delta.u <= 1)
passiv_cond = (eta_x + eta_u <= eta_max_x + eta_max_u) & \
(eta_max_x + eta_max_u <= 1) & \
(delta.x + delta.u <= 1)