During record/playback the page does not auto scroll. I cannot find an option for this.
(Let the page FULLY load. The link to your answer is at the top of your screen)
Auto-scrolling (Lock Playhead): If the Timeline Area shows only a portion of your songs length, then the Playhead will "disappear" when it reaches the right edge of the Project. You then have to manually scroll the Timeline Area to view that section. To avoid this constant interaction, GarageBand provides a feature called "Auto-scrolling. Now when you play your song, the Playhead stays fixed at the center of the Timeline Area and the Time Ruler with all the Track Lanes itself scrolls underneath the fixed Playhead. The little double-arrow icon in the lower right corner of the Arrange window lets you toggle between Auto-scrolling on and off.
This beavior affects the Timeline area in the the Arrange window and the Timeline area of the Track Editor
Hope that helps
<Edited by Host>