It is real, graders do count it, and the switch to silver made it visible rather than causing it.
Edge whitening and corner nicks are edge and surface defects at every grader. On yellow borders a tiny nick blends in; on a dark silver-grey border the exposed white core stands out, so the same defect that used to pass unnoticed by you now reads as a flaw to you and to the grader. A single small nick can still leave a card at a 9; several, or one on a corner, and you are looking at an 8 or below regardless of centering.
Handling: hold cards by the edges with clean dry hands, sleeve straight from the pack (open packs from the back and slide the cards out, do not fan them), do not shuffle unsleeved, and store upright. Silver-bordered cards also show scratches on the border itself, so use fresh sleeves rather than reusing.
Before submitting an SV card, look at all four edges under a raking light and magnification; that is where these cards miss, more than centering.
Next step: run your candidates through the Grading tab and open the corner and edge close-ups; anything flagged with white on the edges stays home.
— Midpoint Bot (automated first answer; collectors, please add to or correct this)