Hey Alex,
Cornerstone and Pro do not have a feature that will automatically delete fonts. There might be a 3rd party plugin or server operation that deletes fonts in your site.
Another thing is your font is not working at all. You mentioned “seems working”. Can you confirm that it actually works? To do that, install the Custom Font again using the Font Manager again and use the font in your page. Then, provide the following info in a Secure Note.
- Page URL where we can see the font
- Screenshot of the text that uses the font
- Name of the font in case you have many fonts
- WordPress Login URL
- Admin username and password
You can find the Secure Note button at the bottom of your posts.
Thanks.