Edit: No bug

[ooli]

Shadow grasp, when it's disrupted by antimagic equipment (Glove of disruption) Still do damage, silence, disarm, but not the Grab.
BUT.. it doesnt break Stealth! So i wonder if it even still use a turn
(see attach)

On the side note... having Glove of disruption equipped, still stay equipped when you learn your first spell (might be intentional, and I like it like that)

EDIT: It was on autocast.. so may be the disrupt trigger, nothing happen, then the regular cast happen. BUT.. that doesnt explain why stealth was NOT de-activated the second time

[Moasseman]

Shadow Grasp is supposed to not break stealth (says so on the tooltip)

Also do you have some autocast-related addon?

[ooli]

Oh! Your right Ambush dont break stealth, my bad!
I indeed use an AI addon, which is basically all autocast.

Now we're left with Spellhunt Remnant still used as a caster. But that's not a bug per se