Hello Serra Baran
Yes, this can be related to the font’s internal metadata.
PowerPoint may identify a font by its PostScript name, which can differ from the family name shown in Font Book. Inconsistent naming between platforms can also cause PowerPoint to substitute another font when opening a presentation.
Since you have already restarted PowerPoint and reinstalled the font, try the following:
- Open Font Book, select the font, and choose the Information button.
- Check the PostScript Name, Version, and font type for every style in the family.
- Look for duplicate or disabled copies. If duplicates exist, use Resolve Duplicates and keep the latest version active.
- Run Validate Font from Font Book. Even if no obvious error appeared during installation, review any warnings for individual styles.
- Confirm that the file is an OpenType font rather than the older PostScript Type 1 format.
You can also prioritize the font for Word and PowerPoint. Quit all Office applications, open Terminal, and enter the following command, replacing the example with the exact, case-sensitive PostScript names displayed in Font Book:
defaults write com.microsoft.office PrioritizedFonts -array "ExactPostScriptName-Regular" "ExactPostScriptName-Bold"
Open PowerPoint, close it after it finishes loading, and then open it once more. Each style has its own PostScript name, so you may need to add every required weight separately.
If the font starts working in a new blank presentation but is still substituted in the existing file, the presentation may contain a different saved font name or an embedded version of the font. Third-party fonts can also have incomplete font data, naming conflicts, or embedding restrictions.
For reference, you can refer to this Microsoft’s official guidance:
font issues in Office for macOS
installing custom fonts for Office.
Feel free reply back to this post if you need further assistance, I'll be happy to help.