[DUPLICATE] Whispers in the Dark =%ilvl

[Thogor]

WoW Freakz item link: https://www.wow-freakz.com/item_finder.php?item=140809&&name=whispers-in-the-dark
Bug description:
Based on my calculation, a 955 "Whispers in the dark" should give 64% increase speed, instead of 51%. "How?"

https://youtube.com/watch?v=-d0qmOtyiIo&t=53:

in this video if u pause it at "0:54" u`ll see that a heroic 895 ilvl trinket give 40% increase speed,i have the same trinket with the same ilvl on Freakz, and it give 41%
https://imgur.com/a/nwkYH2t, instead of 40%.
Now if we watch https://youtube.com/watch?v=jC8va9e62V0:

here at 0:28 u can see that a 905 ilvl trinket give 44% increase speed. So => only 5 ilvl is a 2% increase speed on trinket. if 895 give 40% and a 905 give 44% a 900 should give 42% and so on.

895 - 40%
900 - 42%
905 - 44%
910 - 46%
915 - 48%
920 - 50%
925 - 52%
930 - 54%
935 - 56%
940 - 58%
945 - 60%
950 - 62%
955 - 64%

As wowpedia in (2017-01-18): "Whispers in the Dark: casting speed increase has been reduced by 15%." and now we have a "dicrease" of 51 % on Freakz server. even if it was a 15% decrease u can see that in the one with 895 ilvl the video was posted Published on Mar 4, 2017, and if u watch the calendar it show 4 there, the other video is Published on Apr 9, 2017.

Proof:

Update @ 23-02-2019, 13:19:14

Quick update, the negative buff is bugged aswell (to high) https://imgur.com/a/jyt9WnI. Based on the increase speed buff, the decrease speed should be 0.5% at 5 ilvl. So for a 955 should be 64% increase speed with 22% decrease speed.
895 - 16%
900 - 16.5%
905 - 17%
910 - 17.5%
915 - 18%
920 - 18.5%
925 - 19%
930 - 19.5%
935 - 20%
940 - 20.5%
945 - 21%
950 - 21.5%
955 - 22%