This is the same symptom reported in the Logos 7 forum at https://community.logos.com/forums/t/131480.aspx
I have high CPU usage while viewing the Home page and it continues after going back to desktop layouts, even if I (and Logos) is not doing anything. CPU usage returns to normal only when I close Logos. CPU usage continues to be normal when I launch Logos and use desktop layouts until I go to the Home page, then CPU usage jumps up again.