At the beginning of "The Doctor Falls" (s10, e14), the Doctor
saves the city at the bottom level by changing the cybermen's definition of human to two hearts, thus redirecting them on him and the two Masters.
Later in the episode, two things happen of import to the question, and one in the previous episode. One of the former is that
the patients emerge at night in the solar farm, presumably to collect children.
This means they probably used the elevators, or have been traveling a while. Either way, they are able to identify humans. The other of the former of import is that
the cybermen have to have a lift called in order to identify the level the Time Lords are on.
But in the previous episode
they are capable of identifying humans all the way on the first level.
Therefore, if they
identify humans by two hearts, and they had long range sensors, why couldn't they pinpoint the only three 'humans' on board immediately? Or, for that matter, just follow the trail of broken ceilings their ship crashed through?
Why Couldn't the Cybermen Find the Doctor?