If you created an anchor by clicking (rather than click-dragging) the scene, the anchor does not have any tangents by default. However, you can add a pair of tangents manually.
+
-click
and select Anchor Presets from the Marking
Menu.
Two options appear, Bezier and Bezier Corner.
You can also remove tangents to create sharp corners.
+
-click
and select Anchor Presets from the Marking
Menu.