Thanks for your inquiry. Please note that Aspose.Words requires TrueType fonts when rendering documents to fixed-page formats (PDF, XPS or SWF). Make sure you have all the Fonts installed on the machine you’re using to convert Word document to PDF format. I would suggest you please read the following article:
Perhaps, you are using an older version of Aspose.Words; as with Aspose.Words v188.8.131.52, I am unable to reproduce this problem on my side. I would suggest you please upgrade to the latest version of Aspose.Words i.e. v184.108.40.206 and let us know how it goes on your side. I hope, this will help. I have attached the output Pdf file with this post for your kind reference.