Vim无法加载项目目录下的本地ftplugin问题求助

主目录的.vimrc首行设置了secure exrc并启用了ftplugins，希望在部分项目中覆盖全局ftplugin配置，但Vim仅加载项目目录下的.vimrc，未加载项目目录中的.vim/after/ftplugin/c.vim，全局配置已正常加载。

以下是:scriptnames命令的输出（第10、14、27行分别为全局.vimrc、本地.vimrc、全局ftplugin）：

1: /usr/share/vim/vimrc
  2: /usr/share/vim/vim82/debian.vim
  3: /usr/share/vim/vim82/syntax/syntax.vim
  4: /usr/share/vim/vim82/syntax/synload.vim
  5: /usr/share/vim/vim82/syntax/syncolor.vim
  6: /usr/share/vim/vim82/colors/lists/default.vim
  7: /usr/share/vim/vim82/filetype.vim
  8: /usr/share/vim/vim82/autoload/dist/ft.vim
  9: /usr/share/vim/vim82/syntax/c.vim
*10: ~/.vimrc
 11: /usr/share/vim/vim82/ftplugin.vim
 12: /usr/share/vim/vim82/colors/industry.vim
 13: /usr/share/vim/vim82/keymap/russian-jcukenwin.vim
*14: /home/Common/Прога/Свое/tests/vimtest/.vimrc
 15: /usr/share/vim/vim82/plugin/getscriptPlugin.vim
 16: /usr/share/vim/vim82/plugin/gzip.vim
 17: /usr/share/vim/vim82/plugin/logiPat.vim
 18: /usr/share/vim/vim82/plugin/manpager.vim
 19: /usr/share/vim/vim82/plugin/matchparen.vim
 20: /usr/share/vim/vim82/plugin/netrwPlugin.vim
 21: /usr/share/vim/vim82/plugin/rrhelper.vim
 22: /usr/share/vim/vim82/plugin/spellfile.vim
 23: /usr/share/vim/vim82/plugin/tarPlugin.vim
 24: /usr/share/vim/vim82/plugin/tohtml.vim
 25: /usr/share/vim/vim82/plugin/vimballPlugin.vim
 26: /usr/share/vim/vim82/plugin/zipPlugin.vim
*27: ~/.vim/ftplugin/c.vim
 28: /usr/share/vim/vim82/ftplugin/c.vim

已尝试移除secure选项或全局配置，均未解决问题。

内容的提问来源于stack exchange，提问作者leschtsch