Searching for blocks stopped working for Cyrillic from 14 version

[vjik]

Description

Version 13.9.0:

Version 14+:

There has been a similar problem for a long time: #10775

Step-by-step reproduction instructions

See above.

Screenshots, screen recording, code snippet

No response

Environment info

No response

Please confirm that you have searched existing issues in the repo.

Yes

Please confirm that you have tested with all plugins deactivated except Gutenberg.

Yes

[vjik]

I'm tested this bug in new clean WP 6.0.2 + Gutenberg plugin.