If you can't use ScrollTo behavior, you can shake the screen with events - scroll to player position + random offset. However, this will not work if the player is close to the layout edges and unbounded scrolling is disabled.
Why does unbounded scrolling break your game? You should be able to enable it and limit the scrolling with events:
Scroll to X: clamp(Player.x, viewportWidth(layer)/2, layoutWidht-viewportWidth(layer)/2)