Why does the metric work on pages where there is no code?

Question

Yandex.Metrica

There is a problem, the metric code appears on the page where it is not set.
Why is this possible?
In nginx, js is set to expires 31d, but this should not affect it
. Thank you.

Answer 1

So he's just there.

Answer 2

Let's put it differently, can the previous version of the page remain in the nginx cache?

Answer 3

As they say, page code to the studio!