I am not too familiar with it myself, but I think the node editor may make troubleshooting that sort of thing a little easier, as you can see input and output connections for any given thing. Probably if you are doing some rigging courses you may be introduced to that at some point.
show where those controllers are located in the outliner. fully expand so you can see any constraints involved. what is the rig? is it advanced skeleton? if you use the IK controllers, do they not behave as expected?