Why is the directory display on another site in 1c.Bitrix empty?

Question

1C-Bitrix

I have 1C-Bitrix version 17.0.3. In the "Administration" tab, I see my two sites. The first site displays the Address Program directory. I need to display the directory "Address program" on another.
I migrated catalog templates. The smart filter is displayed fine, but the items in the "Destination Program" directory are not displayed.
Put a stub in the file that outputs a list of items:
<?echo json_encode($arParams['ITEMS']); ?>
Outputs NULL... As if the array is not filled at all.
What could be the problem?..

Answer 1

It turns out that it was necessary to bind in the infoblock settings to the second site)

Answer 2

Are both sites marked in the settings of the infoblock which is a directory? This is the most obvious reason, but the filter should not work either.
In general, there is not much information in the question:
> In the "Administration" tab, I see my two sites.
This is good, but where and how does this relate to the question? Why did you decide to add this information?
> I migrated catalog templates.
Where and for what? How is multisite implemented?
Show component call. Paste the code directly into the question. When doing this, make sure that the code on both sites is identical.