Steps to reproduce

1. vim.exe -u NONE -N
2. :set encoding=utf-8
3. :set breakindent
4. input '\t'
5. Type 'a' until there is one character left before wrapping
6. input 'あ' (double width character)
7. switch normal mord

cursor position is not 'あ'.

Expected behaviour

cursor position is same 'あ'.

Version of Vim

9.1.598-9.0.1826

Environment

OS: Windows 11 Pro
vim: gvim.exe
vim version: 9.1.598-9.0.1826(more older vim-win-32-installer version is no reproduce this issue, maybe cause commit is 6e55e85?)
See: Release v9.0.1826 · vim/vim-win32-installer

Linux is same reproduced.

OS: Ubuntu 24.04(WSL2)
Terminal: mintty
vim version: 9.1.16

Logs and stack traces

no logs and no stack trace.