Question about focus and aperture, how to deal with excess blur?

Question

Photo

Gentlemen, tell me, there are two objects, let's say 2 adjacent lenses.
One stands a little further than the second by 20cm.
With aperture 1.8, only the first lens is sharp, this is logical.
At aperture 4-5, for some reason, the second one does not become sharp either, only not so blurry.
The essence of the question is, why did we increase the aperture reading by 2 times, but did not achieve the sharpness of two objects at once?
Although the distance between them is 20 cm, not 2 meters.

Answer 1

The blur spot diameter is inversely proportional to the aperture value (ceteris paribus).