This very likely indicates that those files don't have the expected contents. You should run the file health check to confirm. They should be reuploaded if needed. If so, you likely need to check your FTP/uploading program to ensure that these files are treated as binary.
Alternatively, your web server may need MIME type settings so that it serves woff2 files correctly (there's some discussion here for Apache:
https://www.thewebflash.com/set-the-correct-mime-types-for-woff-fonts-in-your-web-server/).