A TrueType font file defines a cmap table mapping the character codes to glyph indices. However, when an Encoding is defined in the font dictionary of the PDF, the defined Encoding must override the built-in cmap table.
Currently, when a text fragment is exported with such a font the char code is mapped using the built-in cmap table and not the Encoding defined for the font, which may lead to incorrect glyphs.Workaround
: Change the font of the TextBoxField's widget appearance:
foreach (var widget in field.Widgets)
widget.TextProperties.Font = FontsRepository.Helvetica;