Please see case #ADB-29063356-Y6D4. When converting PowerPoint files that use the custom font "GT America" to PDF using the "Save As Adobe PDF" plugin option, the font is intermittently not retained. After working with support for a few weeks, we found that it only occurs in recent versions of Acrobat. Installing version 22.003.20258 and disabling updates fixes the problem, but this is not a good long-term solution. The support engineer I was working with said to submit a bug report here, but please also check the case notes for full details of everything that's been attempted.