is 1/2 an Aerius i better than none?

Hello to all, this is my first time here, but I am a musician and audiophile since childhood and comfortable repairing most electronics from TV's to Automotive.

The bottom half of my Left mylar plate makes no sound. I vacuumed, then removed drivers and swapped left for right. There was no difference, so I remove both plates and washed with moderate pressure distilled water. Big improvement in the imagery of the working plate, but still only the top half of the other plate makes sound. Both subs sound adequate.

Is this a known issue? Can the mylar be refurbished or recoated? Might this be another issue?

Thanks for helping me bring back the music!

Doc-

It could be that the diaphragm energizer copper lines in the sides of the panel are not making good contact with the mylar film. Make sure that the panels are firmly held in by the side rails and check that there is no separation evident within the sides of the panel.