You may have a drawing object that was added to your chart when viewing a different market or different expiration.
To remove the object, click on the "Object List" icon on the left chart toolbar. Then, remove the object.
Left-click on the object and click Remove, or click Remove All.
If that did not help, right-click in the chart and go to View > Auto Min / Max Price. This will reset your chart back to Automatic scaling.