As a result, CDNs, caching plugins, and web browsers aren't using the new stylesheet with the icomoon font – they're still caching the old stylesheet that references the previous fontello fonts, which are no longer part of the plugin. Because of this, icons are disappearing for some users who upgrade until they purge site caches, CDNs, and browser caches manually.
I propose either updating the version during each plugin release manually or using the current plugin version automatically. This should help with future releases if new icons are added to the font too.
The plugin stylesheet is currently enqueued as version 1.0.5 even though the plugin version is 1.0.10:
(From https://github.com/copyblogger/simple-social-icons/blob/develop/simple-social-icons.php#L393 )
As a result, CDNs, caching plugins, and web browsers aren't using the new stylesheet with the icomoon font – they're still caching the old stylesheet that references the previous fontello fonts, which are no longer part of the plugin. Because of this, icons are disappearing for some users who upgrade until they purge site caches, CDNs, and browser caches manually.
I propose either updating the version during each plugin release manually or using the current plugin version automatically. This should help with future releases if new icons are added to the font too.