The preview actor is searching for the nearest snap point and moving there. When the player moves the preview stays glued where it was and only moves to another snap point it that point becomes the nearest, or fades if no snap point is found. It’s not supposed to move anywhere else. It’s not attached to the player either so if the player moves it should not drift.
At least that’s how the default preview actor works. But if I understand correctly from your question on the marketplace you made your own custom version? Probably something wrong in your implementation?