Some problems with sitemap (slug)

Hello! We have some problems with sitemap (slug).

There are no problems with sitemap on English version of our site https://silkroadexplore.com.
Slug looks ok:

https://silkroadexplore.com/two-countries-two-cultures/
https://silkroadexplore.com/northern-route/
https://silkroadexplore.com/best-travel-ideas-for-you-and-your-family/
etc.

We have recently made a Russian version of our site (https://silkroadexplore.com/ru/) and now have problems with sitemap here, slug looks like this:

https://silkroadexplore.com/ru/%d0%b2%d0%b8%d0%bd%d0%bd%d0%be-%d0%ba%d0%be%d0%bd%d1%8c%d1%8f%d1%87%d0%bd%d1%8b%d0%b9-%d1%82%d1%83%d1%80-%d0%b0%d1%80%d0%bc%d0%b5%d0%bd%d0%b8%d1%8f-%d0%b3%d1%80%d1%83%d0%b7%d0%b8%d1%8f/
https://silkroadexplore.com/ru/%d1%83%d0%b4%d0%b8%d0%b2%d0%b8%d1%82%d0%b5%d0%bb%d1%8c%d0%bd%d1%8b%d0%b9-%d1%82%d0%b0%d0%b4%d0%b6%d0%b8%d0%ba%d0%b8%d1%81%d1%82%d0%b0%d0%bd/
etc.

The problem is probably in using of Cyrillic.

Please advise the plug-in, that can solve the problem. We would really appreciate your help as we plan to fill the Russian version with much content and would like to solve the promblem before this.