There are several possible reasons why a custom font added to IIS for Fast Reports may work for one site but not for another, even with the same settings. Here are a few possible reasons:
Different versions of IIS: If the two sites you are configuring the custom font for are running on different versions of IIS, this can cause compatibility issues. Therefore, depending on which version of IIS your sites are running on, you should use the corresponding version of the custom font.
Different IIS settings: Another possible issue is different IIS settings on different sites. For example, if one site is working with custom fonts over HTTP, and another is over HTTPS, this can affect how the fonts are displayed on the site.
Different font locations: It's possible that the fonts are not located in the same place on two different servers, and this can cause issues with loading the fonts on one of the sites.
Caching: If the font is added to one site, and then you add it to another, the browser may have a cached copy of the old version of the font. This can cause the font to not change when you switch to the other site.
If this is a self-hosted font, it may be necessary to modify the hosting settings of the font to allow access from other domains (perhaps by adding the instance address of Creatio to the Allowed domains list).
To address these issues, make sure you are using the correct version of the font, check if the settings are the same on both servers, make sure the fonts are located in the same place, and clear the browser cache.