It’s usually caused by the killbox beneath the world being too close to the floor and a character is interpolated briefly in to it, causing critical ankle hits.
Pardon the artistic impression of what this might look like but:
The solution is usually to just nudge the killbox further down, so even heavy interpolation stops the player actor from getting shredded but yeah. The boxes are needed as a “when things go really wrong, kill the player so they can at least respawn” (you’ll find them in almost all games where they’re needed so you dont end up endlessly falling in to nothing) but they can, sometimes, as pictured masterfully, cause the problem.