I see Blizzzard have delete this debuff as per information on Hotfixes, Feb10 2020
"Grasping Tendrils is no longer dispellable by Magic dispels and will no longer appear on players’ raid frame UI; it can still be removed by abilities that remove snares.
Developer's Note: We originally made this effect’s snare dispellable so that players could save each other if they were afflicted with it in unfortunate Void Zone-like circumstances. However, we've received feedback that in large-group environments, Grasping Tendrils’ appearance on raid frames could sometimes cause players to overlook more critical debuffs to dispel. We're making this change so players can better see Magic effects in their raid frames as significant debuffs that should be paid attention to and react accordingly."