thanks for reply.
asmecher wrote:Try turning off the "charset_normalization" setting. (This will speed up your installation and is safe to leave disabled; it was useful before UTF-8 was so widely supported but is now a little redundant and occasionally trips over valid UTF8.)
It was so by default, off course. Turning in On was one of other solutions described somewhere in the forum. Without any reaction in my case. It is very unusual situation: usually if there is a problem with cyrillic font support - they are wrong displayed in bulk - every character without an exception, but the case with only two disappearing - this is very strange. These two are not any special symbols - just normal ones like the others alphabet neighbours. And other strange thing is that one of them is uppecase and other lowercase and their opposite cases are displayed normally.