This has happened to me quite a few times but I only just realized what was happening was a bug. The issue is when a slag walker (possibly any skelly) does it's jump attack into it's bite animation. Sometimes if it gets knocked at the right moment or if there is lag you will still get frozen in place like it's doing it's bite animation but the slag walker will behave normally. So if he got knocked away for example (more common) you'll be stuck there with nobody around you for a couple of seconds unable to move (screaming at the screen) - or worse if he didn't get knocked away he'll just do normal attacks while your unable to move. Either way your knight is unable to move for a few seconds without any visible sign as to why.
This bug has been around for as long as the jump attacks, can't find the old thread tough. So:
- Sometimes, zombies get an extra-fast "claw attack" instead of the bites when interrupted. Doesn't like it's meant to be like that, either.
- Possibly related: When interrupted during an "un-interruptable" charge attack (e.g. autogun, troika lines), players are frozen in a similar ways (happened most during pvp or fighting vanaduke, so players and vana might have something in common that can trigger this bug in players/zombies)