Pressing the sneak key and then opening the chat interface will force the input method to switch to Chinese mode.

I apologize for not clarifying things clearly in my comment on MC-306741. This is a similar issue affecting Chinese input methods:

In fact, when using Microsoft Pinyin, under certain circumstances, it does remember the player's last used input language mode. However, I have found that after I sneak (press the Shift key) in the game, the next time I press the "T" key or "/" key, it defaults to Chinese mode and forgets the player's last used input language.

It only remembers the last used input language mode if I never press the sneak key at all.

Expected behavior:

Open chat box → Press Shift to switch language mode → Send message or close chat box → Sneak → Open chat box again → Remain in the previous language mode.

Actual behavior:

... → Sneak → Open chat box again → Always stays in Chinese mode.

This issue occurs not only in the chat box but also in other text-input fields, affecting gameplay such as command input.

The affected input method is Microsoft Pinyin.

(Baidu input method is also affected, even without pressing the sneak key; Sogou Pinyin input method and others are NOT affected.)

Since Microsoft Pinyin is an official Microsoft input method, it should be prioritized for fixing. I do not know why different input methods behave differently.