I've tried a Nordstrand NP4 in several basses and cannot figure out whats going on with it

To get any descent sound from it, I have to raise the pickup so close to the strings it interferes with playing. Any lower, it just sounds weak and...........thin

Dimarzios and Fender P pickups work at a normal functioning height, it's just the Nordy that doesn't seem right.
Any suggestions??