This isn't a glitch, this was actually a change a bit back for damaging supressions, I.E. Malzahar and Warwick in specific. It was a buff. It also shifted where Warwick is positioned on their target after ulting. Basically, you have to physically relocate outside of an AOE around Warwick after his ultimate begins to stop the damage for it, I.E. You QSS the moment her ults. If you stand there, he's still going to deal his full damage to you. This is also true of Malzahar (though his ulti is glitchy as heck as well.)
Using a knockback is generally more effective to get Warwick's damage off someone, I.E. Alistar, Lee Sin, Vayne or Poppy.
I should say a WHILE back. I think it was late S2.
Also, silence doesn't stop suppression. Never has as far as I'm aware. You need a QSS, stun or displacement.