Maximum number of rendered asciidoc documents on one page

Hi everbody

At our firm we are a step from moving our code to Gitlab (yaay :slight_smile:), but we encountered some problems with Wiki and asciidoc. We have a lot of documentation across multiple .asciidoc files, and we also have one .asciidoc file which imports all other files (let’s call that file the main file). The purpose of this main file is to group and render complete documentation from one .asciidoc.
When this file is rendered in Gitlab, first x links are rendered normally (e.g. text, images, formatting is normally rendered). From x+1 link, nothing is rendered, and only clickable links are displayed which open .asciidoc. Opened .asciidoc is not rendered but source of the file is displayed, and nothing else (no left-side menu, navigation bar, nothing which is usually rendered when on wiki).
If page that is linked is manually searched and clicked, page is rendered normally.

This main file contains imports to 100 other asciidoc files, but only first 32 are displayed correctly. After that, only links are displayed. We tried removing first 32 imports (because they are displayed correctly to eliminate any bug in documentation itself), but that resulted with correct rendering of next 32 files.

Has anyone encountered with such issue or have we did something wrong at our side? Or is there some sort of maximum chars to render or maximum number of links per page?
We are self hosting Gitlab (free plan), and are currently on version 12.9.2 (we update it almost every month).

I am also posting some screenshots to show what I am talking about.
This is the start of the main page with first 32 links rendered correctly:

And after 32 links were rendered correctly and without any flaw, Gitlab stopped rendering other documents:

I am also posting the portion of the “source code” of main page to show that all files before and after chapter 32 are included in the same way.