Sell your stuff at The Official PhilMusic-Ads Facebook Group: https://www.facebook.com/groups/PhilmusicAds/
Most probably it was a "fake" D'Addario. Most fakes have stainless steel strings inside (1, 2, 3). These stainless steel strings can't be pulled magnetically by the pickup's magnet thus the weak or almost no sound.
Where did you buy the strings?