Can you take a look at this PDF and let me know if there is an alternate way to perform the conversion that would result in more faithful conversion? Is this something that is fixed in any available version?
I can confirm we are getting results that match what you posted with v21.6.0 (the latest version we have a license for right now), which is better but not 100% see issues posted above. Is there anything we can do to get closer to the original?
A ticket with ID PDFNET-50452 has been created in our issue tracking system to further investigate the issue on our end. This thread has been linked with the issue so that you may be notified once the issue will be fixed.