Cyrillic in username

Hello,

Please help me. Many people enter username at register page using cyrillic (Russian) charaters. Also several use social networks for login where they have name in cyrillic. As result in wp_users in database I have users with such usernicknames: @%d0%b2%d0%b0%d0%bd%d1%8f, for example. In user profiles I see the same situation.
What should I do for works with latin and cyrillic names? I checked database and my rows have utf8mb4_unicode_520_ci.
WP version is latest.
Thank you!