I usually have trouble with Atlas track when the rails are out of alignment. Make sure the rails haven't popped out of the plastic molded rail spikes that are holding the rail to the ties. That usually causes rail alignment issues which means you won't be able to push the pieces together enough to engage the plastic clips.
Alternatively, is this really new track? Maybe it's just fresh and stiff?
I wear those leather gardening gloves for track assembly sometimes because it wrecks my hands if I have dry skin.
