Is this confirmed?
Yes.
Arrowhead confirms Microsoft IME can block Chinese or Japanese movement controls and prevent Korean, Japanese, or Chinese chat input.
Arrowhead confirms two Microsoft IME problems on PC: Korean, Japanese, and Chinese symbols may not type in chat, and Chinese or Japanese IME can prevent movement and controls in-game.
If movement stops while the game remains responsive, record the active Windows input method before treating the client as frozen.
The current Known Issues article confirms both problems but does not publish an official workaround or fixed version.
Editorial only: switch to a non-IME keyboard layout before returning control to the game, then switch back for text. This is a temporary test, not a guaranteed fix.
Include Windows version, input language, IME mode, platform store, game build, failed function, and whether changing the layout restored control.
Yes.
No. Controls are separately named.
No. It is an editorial temporary check.