Also been seeing this a lot. Here's a repro writeup for it:
STEPS
1. Enter any game mode as shiv
2. Unlock slice & dice at any level
3. Stand next to a long, flat wall with few details. Melee range or closer is ideal, but not required.
4. Face the wall at a slight angle. 15-20 degrees off perpendicular produces the most dramatic result.
5. Press 2 to activate slice & dice. No further inputs are required.
EXPECTED
@5: Slice and dice animation lasts it's usual duration. Shiv slides along the wall as the animation is playing.
ACTUAL
@5: Shiv slides along the wall as expected. The animation lasts far longer than expected, occasionally replaying the model animation entirely. During this prolonged animation, the player is unable to act or move.
In my video, the most dramatic examples occur after the ~25s mark.