Fix redirect on the site

There is a site on Wordpress industrial-mountaineering-in -...
on the main page there are headings in the menu: Facade work, Cleaning work, Roofing work, High-rise work, Installation work - they are not indexed and give 404.
Page " Ventilated facades "which runs like a page, not a heading, is indexed fine.

Yandex-webmaster writes that "The page redirects the robot to industrial-mountaineering-in -... Check the indexing of the redirect target."

Most likely, the problem is that links in unicode are formed with different case of characters (capital / small letters) when redirecting from the site are small, the webmaster sees them in a large format, respectively, these are different links, despite the fact that the set characters match.

The task is to make sure that the above category pages are normally indexed.

Write the price, time, how much you can do this work and ask additional questions, if any.