Problem with russian language

[Dimensionnnnn]

Greetings, I have encountered a problem with the Russian language display, I have customized the locales and also customized the paths, so in English everything displays fine, however, when I get to the Russian part I am having trouble getting quality text, I checked my meta tags and I am using utf-8, also if I use sharded Russian text everything also displays correctly, could you please tell me what the problem could be?

[Alexandre-Fernandez]

Hi can you please provide a repository where I can reproduce this problem ?
Showcase the problem and the expected result.

[Dimensionnnnn]

Hi can you please provide a repository where I can reproduce this problem ? Showcase the problem and the expected result.

Greetings, I found that the problem was using a video as a preloader on my page, the strange thing is that it created this effect, but when I started using just