I found this thread, https://kriesi.at/support/topic/missing-icons-after-updating-to-wordpress-5-3-1-and-maintenance-releases/ but it stated that the problem was resolved in 4.7.1. I have a new site that is running 4.7.6.4 and the icons are not displaying in chrome. They work fine in safari.
Hey WSI_Gordon,
Looks like your caching plugin is using cdn.
Please have a look at the following thread:
If you need further assistance please let us know.
Best regards,
Victoria