1-byte-per-symbol font + font-awesome symbols

Hello!
I am using ESP32 and LCD display.
I want to make an application which reads text from SD-card (windows-1251 - encoded text, it is important!), displays it and after editting write to SD-card in windows-1251.
So, I have created my font which contains most letters on positions from 192 to 255 (and some are on others positions, for example letter Ё is on the 168 position) and it does not work because in lv_conf.h it is written

#define LV_TXT_ENC LV_TXT_ENC_UTF8

So, I changed this string to

#define LV_TXT_ENC LV_TXT_ENC_ASCII

And now I can read or write cyrillic letters. But when I want to add icons from font-awesome, they does not work. What’s the matter and how can I solve the problem?