Broken thumbnail (favicon) images for external links

I'm wondering if others are seeing as many "broken" thumbnail(favicon) images to the left of externally linked posts? I'm not sure if it's simply because my browser needs to have visited a site before it will show me the website's default favicon or something else? For example please see below:

Favicon missing

Apologies if this has already been asked/addressed.

Edit: I just tested visiting the site linked and then reloading Tildes and it doesn't update so I assume it's probably on the external site's "end".