WordPress permalinks rewrite rules and Cyrillic

Hello, im trying to setup up custom rewrite rules (like in https://codex.www.ads-software.com/Class_Reference/WP_Rewrite)

My problem is with Cyrillic characters.
Working string:
$newrules[‘(project)/(А)/(\d*)$’] = ‘index.php?pagename=$matches[1]&id=$matches[2]’;
(word with just one character)
Non working strings:
$newrules[‘(project)/([АБ])/(\d*)$’] = ‘index.php?pagename=$matches[1]&id=$matches[2]’;
(2 cyrillic characters)
Also dont work:
[А-Я] (range of cyrillic)
[\x{0400}-\x{04FF}] (range of unicode)

It seems for me as some wordpress problem. Maybe someone can help me? And if i use test echo preg_match(‘/[\x{0400}-\x{04FF}]/u’, $str); with cyrillic str it returns 1, so something with wordpress.