Ste uses Cloudflare's Always Online when set under attack fun

im using mode under attack.
sometime my page got " is currently offline. However, because the site uses Cloudflare’s Always Online™ technology"
when i refresh everything ok.
did i install something wrong?

Are you saying that after you pass through the Under Attack challenge screen, you get a “Currently Offline” Always Online screen?

yes. please help me fix?