What controls the default Blog avatar?

A few months ago after a plugin update, I noted that all of our subsites (sub directory multisite) that had not actively chosen a blog avatar received the super administrator's avatar - when viewed under the blog listing. I am since started using "Blog Templates" to create new subsites and have ensured that there is an appropriate default site avatar, but this has not helped. All new sites still continue to display the super administrator's (my) avatar - which is irritating. Interestingly, when viewed in the admin panel, these new sites do actually have the new default avatar. It's just not being displayed in the blog list.

Can you outline for me how I can control the setting of the site avatar for new blogs. Additionally, is there a simple way to rectify the existing state of affairs? There are 130 subsites and many of these subsites are active sporadically (in other words,

The site in question is blogg.folkuniversitetet.nu