Cyrillic UTF-8 text encoding in comments is broken at save file changes

If to open any CMake/Qbs C++ project, and modify any *.cpp/.hpp* file (e.g. with cyrillic "Привет" comment), and click on "save changes" (or ctrl + s), then the saved comment becomes broken:

1. Create/open CMake/Qbs project.
2. Open e.g. `main.cpp` file.
3. Make sure that encoding is UTF-8.
4. Write e.g. this comment:

 // Привет.

5. Save `main.cpp` file.
6. Watch that the comment is broken and changes to:

// Привет

UPD:
1. Same behaviour and with the

*.h/*.hpp

files which are parts of a CMake/Qbs project.
2. If to rename

*.cpp

extension with the

*.c

extension, then all saves fine.
3. If to open a

*.cpp/hpp/h

files wihich are not a part of a CMake/Qbs projects, then all saves fine.

OS: Windows 11 64-bit ( 24H2, build 26100.3476)