I’ve had this persistent issue of a particular ttf seemingly refusing to be compressed (as reported by webpagetest.org).
Gzip has been confirmed as enabled, including: AddOutputFilterByType DEFLATE application/x-font-ttf.
I finally narrowed the issue to Cloudflare caching.
I’ve executed the following with Cloudflare enabled:
Purge individual file
No change and file still reported as not compressed.
So I disabled Cloudflare and the problem went away with gzip showing 100 score.
With Cloudflare still disabled, I again Purged the individual file and then Purge everything.
Yet as soon as I enable Cloudflare, this file is again reported as not being compressed.