I found the problem. It might be that I have imported categories when EN language was turned on in my Back-office, so these category names saved to EN language primary. When I turn on EN I see these long names, when LT, short ones. But since EN was disabled on my Fron-office, here in the edit section I saw only LT translation with no choice to edit on EN. But because back-office interface was in EN, so EN category names were provided even EN is not active on front-office.
So I have deleted EN language from the website and everything has fixed!
Thanks for your participation PCQUATRO!
P.S. How to mark this thread as solved? 
Edit History
I found the problem. It might be that I have imported categories when EN language was turned on in my Back-office, so these category names saved to EN language primary. When I turn on EN I see these long names, when LT, short ones. But since EN was disabled on my Fron-office, here in the edit section I saw only LT translation with no choice to edit on EN. But because back-office interface was in EN, so EN category names were provided even EN is not active on front-office.
So I have deleted EN language from the website and everything has fixed!
Thanks for your participation PCQUATRO!