Since CR4, Connections has a new community overview, avaliable on https://cnxhost.com/communities/service/html/allmycommunities. This page uses the new IBM Plex font from a third-party cdn called unpkg.com. I already opened a support ticket at IBM, but they said it's an enhancement, which should be posted here.
I disagree for several reasons:
Please fix this by switching to local files as IBM Connections already do with any other ressources (images, css and js) before. It's okay to have external CDNs as optional functionality, which could be enabled. But connections on prem shouldn't force it's customers to use external third party CDNs here.
My current workaround is to download the font on our webserver and search/replace the unpkg.com urls in the Connections CSS file. But this is a hack that may cause problems on updates, so we need official support for self hosted font files without doing unsupported core changes.