[swarmee]

I don't think that's it. They are still slammed right now because Aug 1 they changed their bulk submission prices from $7 to $8 a card for orders over 100. Everyone and their mom sent in a submission to beat that deadline, and they are still digging out from under it. Until then, everyone had been holding bulk commons for the last year and a half waiting for a monthly special to reduce pricing to $5-6 per card. Once the bulk pricing increase was announced, people who were holding out hope for a return to cheaper grading prices gave up that hope.
Heck, BGS still can't dig out of all of their "nonguaranteed" orders picked up at and after the 2017 National. Most of those orders took one year to complete and mail back to the owners of their cards. You would think that having to pay for card grading a year before getting them back in your hands would hurt their nonguaranteed business, but the delays are still approximately a year on that service. At least PSA doesn't charge you until the cards have been graded.