Pagination hangs in the bitrix admin section, where to dig?

Question

1C-Bitrix

Good afternoon, there was a glitch with pagination in the Bitrix admin panel, when you go to the first page of pagination, it freezes, the circle on the pagination page spins and nothing happens, switching the number of elements on the page does not work. You can go to all pages except the first one. If you go to another section with content, you immediately get to page 2.
When you change ?PAGEN_1=3 to ?PAGEN_1=1 - 404. There are no errors in the console. Working with the URL bitrix/admin/iblock_list_admin.php , Bitrix was not updated, support ended in 2015, I think no one could get into the admin panel, the front should not influence.
Who had such a situation, how to win?

Pagination tries to get 1 page in pagination, but redirection to http://domain/folder/folder/domain/docs/bitrix/admin/i...
folder/folder - do not exist and the domain gets into the URL twice. Looked at urlrewrite in several places - empty