Duplicate author title tags

Hey guys how are you ?
I’m having an issue with duplicate title tags.
My Author archives title template is set to: %%name%%, Author at %%sitename%% %%page%%

But when I move between the different author pages I get just the author name as title (which causes duplicate content). Take a look here.

Any idea how I can fix this ?
Thanks.

https://wordpress.org/plugins/wordpress-seo/