Enabling (or Disabling) Insertion Follows Playback
To enable (or disable) the Insertion Follows Playback option, do one of the following:

Select (or deselect)
Options > Insertion Follows Playback.

In the Edit window Toolbar, click the Insertion Follows Playback icon so that it is highlighted (or unhighlighted).
Insertion Follows Playback icon

Press Control+N (Mac) or Start+N (Windows) to toggle the Timeline Insertion/Play Start Marker Follows Playback preference on and off.