Modular Control Rig - Foot breaks the leg module

If you set up a Leg module control, the ik/fk switch + the leg hierarchy is recognized. The IK/FK controls work without issues. As soon as you drag/drop a FOOT module, it removes the leg controls and no foot controls are present. Please let me know if this is a bug or a common setup the user needs to do before assigning the foot module beforehand.
Thanks.