Magento 2.4 Critical CSS enabled, 3rd party icons missing
I am trying to optimize my M2.4 site by enabling Critical CSS, but I am running into an issue that I can't seem to resolve.
I am using Google Material icons throughout the site which works as intended, until I enable critical css. When enabled, the icons disappear and I only get the text value of the icons.
I have confirmed that the critical.css file exists and is getting written to the head of the page code. I have tried importing the icons via default_head_blocks.xml and also in css using @import. Neither method seems to work when critical css is enabled.
Hopefully one of you can suggest a fix here. I'd really like to introduce this option to speed-up the site. Let me know if any further info is needed.