You're not gonna believe this, I found the problem.

It was /usr/lib/locale

I've installed locales which is not installed by default, but for boot the old pre-locales-install content is needed, so I bindmount the folder after boot.

Turns out I messed up somehow sometime and had the bindmounted /usr/lib/locale empty and for this reason it was cycling forever with the Russian routing, but for some reason working with Czech.

Anyhow, I've restored contents of the /usr/lib/locale dir properly and now it's working.

Ugh... Thanks for help.

Anyhow, please still implement if you can the Cyrillic identification and substitution, as continuous `letter A 6 7 5...' is not too great :O)