Poor fit at the control plate is rampant on Fender j basses and if you have a deluxe or some other kind of variant, best of luck.
I often think of it as the jazz gap because it is the one place I always expect to have fitment issues. If I had my druthers, I rather see the PG come long at the plate/guard joint to give me a little room to get a parallel match. The car dogs call it diming the joints, where all the joints are parallel and no wider than the width of a dime, but for a PG to control plate fit, I prefer a perfectly parallel butt joint there. Sometime to get that fit you will need to ease the control plate forward a bit after matching the joint to avoid the unsightly crooked gap or in some cases a gaping chasm through which one can actually see wires.
"Strictly speaking, there is no certainty, there are only people who are certain." -anon-