I also have white squares as seen in the video. My point is though that the white squares I have seen on muliple cards i have gotten from PSA and they never show up in the scans. Which makes me wonder if the white squares are on the card after it is scanned somehow.
Also another thread that goes over this. And looks similar. Has an entire youtube video of the guy cracking the card out of the case (8k psa 10 card O_O) .
He was able to wipe it off but took a lot of water and wiping. And it happened again somehow after he got it regraded.