Why don't breadcrumbs work?

Question

DLE

The DLE 10.1 engine is installed, there, in theory, breadcrumbs go as standard, but during the check of micromarking from Yandex and Google, both PSs show that they are not there. What could be the problem?

However, at some posts they work (on a small part). And why is the video added to some pages, the same as the breadcrumbs, but not to others?
However, checking these pages shows the same as those that do not display breadcrumbs.

And for some reason, Google does not see the description

Answer 1

Breadcrumbs can also form in the absence of micromarking on the pages. And appear in the issue depending on the request itself.
(For example, if the page has many links from other pages with the same key and its presence in the title of the page of the recipient of these links).
However, take a look at the actual code for these breadcrumbs and see if they have up-to-date markup.
At the expense of description in Google - the question is not disclosed. But first of all, again, I would recommend taking a look at the code - this also happens:
and it turns out that the description in this case is one word "Serial".