SEOmatic for some reason isn't picking up any 'Title' fields from the entries, which leaves it displaying '| SiteName' within the browser tab. Currently my 'Site SEO Title' is empty, but can this accept Craft variables to inject the page title?
Have you created a new
SEOMatic Meta fieldType?
I don't know whether there is another/better way of doing it, but what I do is create a new field of type
SEOMatic Meta, then assign this field to the entry types of the pages you want the title to be made available to SEOMatic. There are all sorts of options within this field, but one of them allows you to select which field the title is pulled from.
More info on the
SEOMatic Meta field can be found in the docs.