Symbols Preview Correctly but Like a Square in PDF
PdfSharp is restrictive about which fonts support Symbol characters.
The font 'Segoe UI Symbol' supports extended symbol characters when rendered by PdfSharp, So changing the text, embedded html, or field font family to 'Segoe UI Symbol' should solve this issue.
Example HTML with embedded symbols, first with default font, second with explicit Symbol font.
<html> <body> <h1>Symbols with font that does not support symbols in PdfSharp</h1> <p> ★★★★★★ </p> <h1>Same Symbols with font that does support symbols in PdfSharp</h1> <p style="font-family:Segoe UI Symbol; font-size: 30pt;">★★★★★★</p> </body> </html>