The screen blinks when I use MatchupWhereAmI??

[0BananaBig0]

Explain the issue

My .vimrc

" for vim-matchup plugin
let g:loaded_matchit = 1
" 去掉讨厌的有关vi一致性模式，避免以前版本的一些bug和局限
set nocompatible
" 开启256色支持
set t_Co=256
" 不少插件的信息更新都会需要这个时间
set updatetime=33
" 打开文件时进行解码的猜测列表
set fileencodings=utf-8,utf-16,utf-32,ucs-bom,shift-jis,gb18030,gbk,gb2312,cp936,big5,latin1
" 把当前文件转换为当前系统编码进行处理，这里为utf-8
set encoding=utf-8
scriptencoding utf-8
" 禁止生成临时文件
set nobackup
set nowritebackup
set noswapfile
let g:plug_url_format = 'https://githubfast.com/%s.git'
call plug#begin('~/.vim/plugged')
Plug 'andymass/vim-matchup'
call plug#end()

My vim version

VIM - Vi IMproved 9.0 (2022 Jun 28, compiled May 04 2023 10:24:44)
Included patches: 1-1378, 1499

Steps

gvim a cpp file
execute MatchupWhereAmI??
the screen blinks

Maybe my previous code can be a reference?

function! ShowCurrentModule()
let l:module_line = search('module', 'bnWz')
let l:module_name = getline(l:module_line)
let l:module_end_poisition = strridx(l:module_name, '(')
if(l:module_end_poisition > 0)
let l:module_name = strpart(l:module_name, 0, l:module_end_poisition)
endif
let l:module_name = strpart(l:module_name, stridx(l:module_name, 'module')+7)
while(strpart(l:module_name, 0 , 1) ==? ' ')
let l:module_name = strpart(l:module_name, 1)
endwhile
echo 'module -->' l:module_name
endfunction
function! ShowNearestClassOrStruct()
let l:class_line = search('\n'.'class', 'bnWz')
let l:struct_line = search('\n'.'struct', 'bnWz')
if(l:class_line > l:struct_line)
let l:nearest_name = getline(l:class_line+1)
elseif(l:class_line < l:struct_line)
let l:nearest_name = getline(l:struct_line+1)
else
let l:nearest_name = 'No class/struct can be find.'
endif
let l:nearest_end_poisition = strridx(l:nearest_name, '{')
if(l:nearest_end_poisition > 0)
let l:nearest_name = strpart(l:nearest_name, 0, l:nearest_end_poisition)
endif
echo l:nearest_name
endfunction