I found the solution, as suggested by a member of my local community.
There was an opacity set to 0 on the CSS as soon as the page loaded. Because of this new setting, the content would remain in the DOC, but “disappear” from the content.
Although the real root of the problem wasn’t found after all (why the page was adding an opacity of 0 after loading), it was enough for me to bypass it by adding a new rule to the CSS and force opacity 1.