i tested this bug on map buak (multiplayer) with maple ladder
this probbaly doesnt work for ladders that are a part of map but im not sure
so to replicate this bug you need any gun or something that after use has animation and run into the ladder during reloading or using item, also sometimes player can get stuck behind the ladder

it does work with: (unlisted things are untested)
-reloading weapon
-changing filters
-eating
-healing
-using mele (normal and stronger attack)
-using rest emote
-walking backwards or sideways (doesnt always work)

and doesn't with:
-inspecting
-using bayonet attachment
-emoting (excluding rest)
-changing clothes
-punching

video showing some ways to replicate this bug:
https://www.youtube.com/watch?v=iZA0uo-co6Q