A problem when Korean is typed into a WPF RichTextBox. (Windows11 MS IME)

• .NET Core Version: .NET Core 3.0, .NET Core 3.1, .NET 5.0, .NET 6.0, .NET 7.0
• Windows version: Windows11 (Build: 22623.1037)
• Does the bug reproduce also in WPF for .NET Framework 4.8?: Yes

Problem description and Actual behavior:

1. After selecting the text, when I type in Korean, the input does not work (NotePad is fine).

1. When typing Hangul (Korean), there is a problem that it stops(lag) and incorrect typing occurs.

Expected behavior:

1. The selected text area should be cleared and replaced with the character I typed.

2. It shouldn't be slow and it types properly.

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All issues are not reproducible with the option to use the old IME.