Hi Corben,
Thank you for contacting Syncfusion support.
We have checked the reported issue by drawing the text with TTF font in NET Core 5.0 on our end, but it is working properly. We can add text using the font file from local file system by providing the path of the PdfTrueTypeFont location. We have attached the sample and output document for your reference. Kindly try the sample with input TTF file on your end and let us know the result.
Please refer the below link for more information,
If still you are facing an issue, we request you to share the modified sample with input details ( TTF file, input text), complete code snippet, error log or lock information, product version to reproduce the issue. So, that it will be helpful for us to analyze and assist you further on this.
Regards,
Gowthamraj K