1. Go to https://www.google.com/analytics/ 2. Click on "Access Analytics" 3. Refresh a page with Cmd + R 4. Since Email gets the focus, try typing it 5. Nothing gets entered despite the field has actually got focus and the cursor is blinking in it I also noticed this before on 10.5 and earlier nightlies, not only on Analytics. Might have to do with JavaScript that relates to the particular field.