This is the case for many, many abilities, hard to tell if it's a bug or intentional since characters like vyper explicitly have no abilities that stop the slide. I do hope they actually change it to allow you to slide.
Here's a list of most abilities that do it (excluding abilities like Kelvin 2 or Infernus 2 where it makes sense why they stop you):
Dynamo Rejuvenating Aura (3) - Before T3 upgrade
Haze Sleep Dagger (1)
Holliday Powder Keg (1) and Bounce Pad (2)
Infernus Napalm (1)
Ivy Kudzu Bomb (1)
Kelvin Frost Grenade (1)
Lady Geist Life Drain (2), Malice (3), and Ultimate
Lash Flog (3)
McGinnis Mini Turret (1), Medicinal Scepter (2) and Ultimate
Mirage Fire Scarabs (1)
Mo and Krill Scorn (1) and Sand Blast (3)
Paradox Pulse Grade (1), Time wall (2)
Pocket Flying Cloak (2)
Seven Lightning Ball (1), Static charge (2) and Power Surge (3)