Following the score during playback
Sibelius automatically follows the score during playback, and automatically zooms out, so that you
can see the music as it plays. You can navigate around the score during playback just the same as
when playback is stopped, including changing the zoom level (and Sibelius will remember your
chosen zoom level next time you play back).
You can change this behavior using the options on the Score Position page of File > Preferences
(in the Sibelius menu on Mac) – b 1.26 Preferences.