Thank you so much for your answer!

With your answer, you gave me a solution to the problem.

I turned off the page animation in the theme settings in Page Transition .. And now the comment form loads without problems!

Good luck to you!

I'm really sorry, but this cannot be fixed by wpDiscuz side. During the navigation on your website the pages are not being reloaded, thus the CSS and JS files cannot be loaded.

I may suggest you contact the theme support with this question. Probably they may provide some solution for this. 

I still do not understand, do you have an answer to my question or you simply do not have it?

I spent three days in useless correspondence, expecting a more or less intelligible answer to my question from your support service, but in the end, unfortunately, I did not receive anything :(

I disabled all plugins one by one, even WPBakery Page Builder, but the problem persists unfortunately.

You can see it on the same links that I gave earlier.

Thanks

Please deactivate the plugins/theme one by one and check after each deactivation to find a problem maker. 

Please keep the cache plugin deactivated in this testing process. 

Here is a link to the home page of the site

http://www.russian-american.design/projects/

There I left only the portfolio tape.

Please click on any of the pictures in the portfolio and follow the link where you will see a non-working comment form.

Thank you

Could you please leave some example URL? Please keep the cache plugin deactivated to allow us to check the issue. 

Yes, WP Fastest Cache plugin installed.

but even if I deactivate the caching plugin the problem persists.