Pictures from another GLPI domain are not displayed?

Question

Apache HTTP Server

Good afternoon!
I’ll make a reservation right away, how much you don’t study, which means you won’t be everything. In the settings of the web server, and indeed in linux, I am rather weak. To be honest, I'm just dumb at everything. if you give an answer, give it at a discount to the dementia of the author of the topic :) We
continue the war with GLPI.
I thought everything, it seems that the main functionality is set up and it’s quite nice to work like that, I’m slowly implementing it (I teach users to apply, they won’t be poked until you poke them, they won’t figure it out themselves, even with the instructions, but this is already off topic :)), and then an unpleasant fact turns out . Pictures uploaded from another domain are not displayed on other domains.
I will outline how I have it, the details and the actual problem.
There is Debian, it has LAMP, it has GLPI.
Debian GNU/Linux 9.9
GLPI 9.4.3
Apache/2.4.25
I have 4 companies, each has a domain + my site. I registered 5 subdomains from the main one and linked DNS to the address of my server, the result is:
tp.domain.ru
tp.domain1.ru
tp.domain2.ru
tp.domain3.ru
tp.domain4.ru
Each organization works with the portal from its own domain (so as not to confuse them and so that there are no stupid questions, what kind of domain is this, etc.)
chown -R www-data:www-data /var/www/glpi/
chmod -R 755 /var/www/glpi/
so to close directory browsing in /etc/apache2/apache2.conf added (because the server is completely under 1 service, I see no reason to configure each config for each domain separately)
Options Indexes FollowSymLinks
AllowOverride None
Require all granted
Options All -Indexes Actually
, this is all that I configured by rights (but this is not accurate, you won’t remember everything when I already accustom myself to logging everything ....).
I think the introductory information is enough, now to the topic of the question. I’m almost sure that someone simply doesn’t have enough rights for something, but I don’t understand what exactly.
The problem is in the FAQ (and not only in them. I can add screenshots to the application, I work under tp.domain.ru, but the user from tp.domain3.ru does not see these screenshots, only if you click on them, they open in a separate window ). I am writing a FAQ from the main organization with tp.domain.ru, I set it to be available to subordinate organizations, i.e. I am writing one FAQ so that it would be available to everyone at once. I make out Krasvio, add screenshots... but other domains don't see screenshots.
I add a screenshot from domain.ru, from other domains (domain 1 2 3 4) they are not visible if you log in from the same user but through domain.ru - everything is visible. it means that it's not about the rights inside GLPI, but about file access rights on the server side.
Empirically, it was found that if you go under domain3 (or any of them) and add pictures from under domain3, then they are displayed correctly for users coming under domain3.
The address of the images is written https://tp.domain.ru/front/document.send.php?docid=24
I tried to make relative paths (through the html editor instead of https://tp.domain.ru/front/ I did /front/) did not help, the system automatically registers https://tp.domain.ru/front/.
If you click on the line where the picture should be, the picture opens in a separate window. it means that there are rights to the file in the principle, but I can’t understand why it’s not loaded as img :(
below is the screen ...
As an option, you can, of course, let everyone through one domain, but I don’t want to show my main site to all clients (again, because of stupid questions, they passed), but this option is not suitable. Where exactly did the dog dig? I only hope for you ... Google will soon ban me for stupid questions that I can’t find an answer to :(