So the clipping path still has the content outside of the clipping path which is what is causing the problem becuase the object still exists. If the pattern was a pattern fill you would not have the problem or you can use the Pathfinder instead of using a Clipping path.
Why it is happening:

How to fix the clippng path issue:
Step 1: If you have a clipping path, release it Object> Clipping Path> Release or Make/Release Clipping mask in the Layers Panel 
Step 2: Select the pattern and the Clipping Path. (Make sure you have a copy of the Clipping Mask Path to keep for the outline stroke) Once all the items are selected with the non-pattern path on top, Choose the Crop Icon in the Pathfinder Section of the Pathfinder Panel.
Step 3. This is not a step but if you choose the outline view you will see that the path does not exist outside of the original clipping path area. So problem fixed.
