First things first....you're talking about bindings.....go to a shop and get them to look at it. I might be able to shed some light on your problem though...
How old are your Griffons? All bindings develop some movement in the toe piece over time. Until a few years ago Griffons suffered from this but then the AFD (the little plate that slides side to side) was fitted with an elevation adjustment so you could lift the AFD when this movement started becoming a problem. If you have the bindings before this design then the shop might add some tape to make your boot fit better. Or your bindings might just be worn out. At the end of the day we're talking about your knees here....take your gear to a shop.