Why would a model loose snapping control? I copy a group of components ( a drawer assembly) in order to start to nest together to calculate material quantity. While manipulating the items snapping does not work as expected i.e. snaps to some point as normal but completely ignores other snap points? I’m attaching the model..so try moving the blue component to see what I mean (if it replicates)
If you create a component on an ungrouped/uncomponented face, that component will automatically be given gluing properties. Maybe that’s what happened in your model?