I've been running Angular and Material for some time, but this issue suddenly showed up and has me stumped. I'm running my Angular app From IntelliJ and this started showing up in my console.
Access to font at 'https://fonts.gstatic.com/s/materialicons/v48/flUhRq6tzZclQEJ-Vdg-IuiaDsNc.woff2' from origin 'http://localhost:4200' has been blocked by CORS policy: Request header field x-ijt is not allowed by Access-Control-Allow-Headers in preflight response.
And my icons quit showing up.:(
I have found this discussion here:
https://github.com/google/WebFundamentals/issues/6881
But am not running that Akamai plugin referenced.
I also found this discussion, but that seems to be nginx related.
https://deliciousbrains.com/wp-offload-media/doc/configure-cors-to-resolve-web-font-issues/
I am running Chrome as my debug browser from IntelliJ.