There could be a couple things causing this...
String height too low and it’s bottoming out on the fretboard
Pickup not high enough (active pickups should be a close as possible without hitting strings)
Saddle for B loose or any bridge screws loose
String choice Warwicks love steel strings
Make sure gauge of string isn’t too big for saddle where it isn’t seated properly
What pickups? Stock active MEC’s?
“If you are not building your dream then simply someone else has hired you to build theirs”