Cyrillic symbols are not available for the input in the cell of the spreadsheet.
When the keyboard layout is english, the user can just one more click on the cell and than start typing, the result is – the symbols will typed in the cell.
But, when the keyboard layout is russian, and the user just one more clicks on the cell and then try to typed cyrillic symbols, the result is – nothing happened, no one cyrillic symbols is typed.