Custom RSS feed is generated in the wrong encoding (windows-1251 – > utf 8

Good afternoon.
I use the plugin on a Russian-language website. When I inserting the imported feed on the page, there are no problems – it is displayed as it should be. But when I tried to make a custom rss feed (/wprss), it was generated with Russian-language content in the wrong encoding.

Like this:
<title type=”html”>Дополнительные меры безопасности обсудили СЃ директорами школ РЅР° совещании РІ управлении образования</title>

The page I need help with: [log in to see the link]