couldn't highlight current cursor word.

[iysheng]

Explain the issue

Most issues are related to bugs or problems. In these cases, you should
include a minimal working example and a minimal vimrc file (see below), as
well as:

1. What vim version are you using? If using neovim, Are you using
   tree-sitter or classic matching? ** Vi IMproved 9.1 **
2. Steps to reproduce
   use vim-plug install vim-matchup with version commit id ff3bea6
3. Expected behavior
   high light current cursor word as expected
4. Observed behavior
   no highlight
   If your issue is instead a feature request or anything else, please
   consider if minimal examples and vimrc files might still be relevant.

Minimal working example

Please provide a minimal working example, e.g.,

int abc, def;

abc = 0;

{

}

Minimal vimrc file

Please provide a minimal vimrc file that reproduces the issue. The
following should often suffice:

call plug#begin()

" List your plugins here
Plug 'sainnhe/everforest'
Plug 'preservim/tagbar'
Plug 'preservim/nerdtree'
Plug 'bagrat/vim-buffet'
Plug 'itchyny/vim-gitbranch'
Plug 'itchyny/lightline.vim'
Plug 'chazy/cscope_maps'
Plug 'ycm-core/YouCompleteMe'
Plug 'preservim/nerdcommenter'
Plug 'nathanaelkane/vim-indent-guides'
Plug 'ayu-theme/ayu-vim'
Plug 'nordtheme/vim'
" Plug 'luochen1990/rainbow'
Plug 'guns/xterm-color-table.vim'
Plug 'andymass/vim-matchup'
Plug 'bash-lsp/bash-language-server'
call plug#end()