Why did relative links become absolute?

Question

PHP

Hello!
Usually when you specify relative links, for example:

<a href="#reg">Регистрация</a>
<a href="?sort=asc">Сортировка</a>

Then these links lead to the same page with the addition of these "variables". But now, for some reason, on the current project, all these links lead to the main one, for example: mydomain.ru/#reg, mydomain.ru/?sort=asc. You have to add the full path to the page to these links. The question is how to avoid this and what is the problem, in the server settings, where does it change?
CMS MODX.
Please tell me, I have not encountered such a problem before. Thank you.

Answer 1

And an element <base>(or maybe an attributexml​:base ) in the code is not tucked into the code (may be present in static HTML or inserted by a script)? Then it explains.