Why do some contacts in google chat show up as email instead of first and last name?

Question

Google

Good day to all. I ran into a problem that some employees in google chat contacts are displayed as email, and not first name last name. As I understand it, the data is pulled there from the profile of each user, and one could assume that the contact does not have a Google profile filled out, BUT other users have the same contacts displayed correctly.
Here is a screenshot of my chat contacts:

And here is a screenshot of an employee:

The user with the arrow is Igor Karev. In my contacts, he is displayed correctly and his profile is full. And so enough for a large number of users ...
Who faced? In which direction to dig?