I may be found the point to fix.

diff --git a/intern/ghost/intern/GHOST_ImeWin32.cpp b/intern/ghost/intern/GHOST_ImeWin32.cpp
index 47b5f5688df..26a019e6762 100644
--- a/intern/ghost/intern/GHOST_ImeWin32.cpp
+++ b/intern/ghost/intern/GHOST_ImeWin32.cpp
@@ -98,6 +98,7 @@ bool GHOST_ImeWin32::IsEnglishMode()

 bool GHOST_ImeWin32::IsImeKeyEvent(char ascii)
 {
+  printf("key code: %x\n", ascii);
   if (!(IsEnglishMode())) {
     /* In Chinese, Japanese, Korean, all alpha keys are processed by IME. */
     if ((ascii >= 'A' && ascii <= 'Z') || (ascii >= 'a' && ascii <= 'z')) {
@@ -106,7 +107,7 @@ bool GHOST_ImeWin32::IsImeKeyEvent(char ascii)
     if (IsLanguage(IMELANG_JAPANESE) && (ascii >= ' ' && ascii <= '~')) {
       return true;
     }
-    else if (IsLanguage(IMELANG_CHINESE) && ascii && strchr("!\"$'(),.:;<>?[\\]^_`", ascii)) {
+    else if (IsLanguage(IMELANG_CHINESE) && ascii && strchr("!\"$'(),.:;<>?[\\]^_`/", ascii)) {
       return true;
     }
   }

A screenshot of above build.

The patched build.
https://www.futuregadget.com/file/blender-T94434-fixing-build-20211228.zip

I think it because Microsoft Pinyin IME is a little different?
/ = /
\ = 、
I can get the same results in other software.

I don't know why, but I don't seem to be able to confirm this bug. When I use Microsoft input IME in other software, \ = 、

Ah, I can confirm this now, I'm OK because I enable this before:

In T94434#1279546, @Harley Acheson (harley) wrote:

@Takahiro Shizuki (sntulix) - You should to create a new new diff and when you submit it give it a description like "Fix T94434: Windows IME Pinyin Forward Slash". I'll look out for it and edit if needed. Or if you need any other help let me know.

I see, thank you.

I did it. D13771

Hi.

---

Ah, I can confirm this now, I'm OK because I enable this before:

OK.
Thank you.

And, I checked with Blender patched the diff above with the patterns Microsoft Pinyin compatible mode is enable and disable both.

• Patched results inputting / at edit text box.
  • compatible mode is on: "、"
  • compatible mode is off: "/"

• Patched results inputting / at edit text box.
  • compatible mode is on: "、"
  • compatible mode is off: "/"

Yes, I forgot that I had been using the compatible mode all the time, and I didn't understand this bug for a while. Sorry for the noise~