Thanks for your inquiry. Please note that Aspose.Words mimics the same behavior as MS Word does. If you convert your HTML to Word document using MS Word, you will get the same output.
In order to insert a Symbol using Aspose.Words, you must know it’s hex or decimal code. You can find the Symbol character code inside Insert Symbol dialogue in Microsoft Word. Once you know the Symbol code, you can use the following code to insert it using Aspose.Words:
Document doc = new Document();
DocumentBuilder builder = new DocumentBuilder(doc);
// Insert symbol.
builder.Font.Name = "Wingdings";
builder.Font.Size = 20;
doc.Save(MyDir + "Out.docx");
Could you please attach your input HTML document here for testing? I will investigate the issue on my side and provide you more information.