Missing notifications icon on user profile page

Okay, yes, it works fine with Cassiopeia. The missing icons are all the same. class="fa fa-globe" or some variant thereof. I've poked around with the inspector and have attached screenshots and bits of code. What next? Is this something that can be fixed by an override? If so, how and where? Is the root problem with the template, or CB?
Please advise how I can get this fixed and/or what to do next.

Your template maybe restyling Fontawesome in some way that's breaking the styling. I'm guessing they're changing the font-family of Fontawesome for some reason.

Switch back to your template and first try using Fontawesome 6 Compatibility in CB > Configuration > Integrations and see if that resolves your template conflict issue. If your issue persists you'll need to contact the developer of your template.

 Fontawesome 6 Compatibility was already on.

The problem seems to be browser dependent, to some extent. It was broken on Firefox / Chrome / Edge on a Win 11 laptop, however it displayed correctly using Safari on an old iphone 6 SE!

We've found this hacky workaround:
Could you review the hack and see whether that points to any adjustment in the CB code please?

No adjustment is needed in CB. Your 3rd party template is clearly doing something to Fontawesome to result in the break as it works fine with Cassiopeia default template. We do not apply custom fixes for 3rd party templates, sorry there's just way too many templates for us to have to be responsible for that. I recommend contacting the developer of your template, but you're of course welcome to apply whatever custom CSS fixes you find necessary.