The site title and tagline appears twice in the address bar when using Safari. In the browser tab it is, however, only shown once. My assumption is that this has something to do with the parent and child themes but I can’t pinpoint the cause. Please let me know if there is a solution to this?
You could try deactivating your plugins to see if any are causing that – particularly an SEO plugin might be. Or it may just be a Safari thing – are you using the new OS/Safari?