An issue where devices with windows OS that uploaded font files would cause a missing mime type was found. This missing mime type meant our network could not compress the file previously. A font file could be anywhere on average from 20kb to 500kb in file size, our app may load 10 - 30 fonts - these uncompressed files were causing an impact on page speed.
We have addressed this issue by updating all existing font files that were affected to ensure they can now be compressed and provided a fix to the font upload form on our app to prevent missing mime types from occurring again.