Some users told us that they see a "Set as startpage" / "Install extension" pop-up every time they sign in to start.me.
When you see this pop-up and click the "Skip" button, a cookie will be set on your local PC to not show this pop-up again.
Make sure you have cookies enabled in your browser. Otherwise the pop-up will reappear.
If you want to enable cookies for start.me only, that should work. In your browser go to Options/Preferences > Privacy > Exceptions and add "start.me" as exception.