Coc.nvim doesn't work correctly

Question

Yesterday, I installed coc.nvim in vim on windows. I remember that it showed up the suggestion tab. But today, I removed go and visual studio, then it didn't show up anymore. I tried to reinstall Go, Visual Studio, but it still didn't work (no error message appeared) then I reinstalled coc.nvim in Vundle, then reinstalled coc-clangd, coc-json, coc-tsserver, but nothing changed.

Here is the gif explaining it.

Here is my _vimrc (I'm using Windows)

" PLUGINS ---------------------------------------------------------------- {{{
set rtp+=~/.vim/bundle/Vundle.vim
call vundle#begin()
Plugin 'VundleVim/Vundle.vim'
Plugin 'https://github.com/preservim/nerdtree'
Plugin 'https://github.com/joshdick/onedark.vim'
"Plugin 'Valloric/YouCompleteMe'
Plugin 'https://github.com/vim-airline/vim-airline'
Plugin 'neoclide/coc.nvim', 'release'
call vundle#end()
" }}}
"CONFIGURATIONS --------------------------------------------------------------- {{{
"let g:ycm_global_ycm_extra_conf='~/.ycm_extra_conf.py'
"let g:ycm_confirm_extra_conf = 0
"Turn syntax highlighting on
syntax on
"Clipboard settings
set clipboard+=unnamed  " use the clipboards of vim and win
set paste               " Paste from a windows or from vim
set go+=a               " Visual selection automatically copied to the clipboard
" Disable compatibility with vi which can cause unexpected issues.
set nocompatible
" Enable type file detection. Vim will be able to try to detect the type of file in use.
filetype on
" Enable plugins and load plugin for the detected file type.
filetype plugin on
" Load an indent file for the detected file type.
filetype indent on
" Add numbers to each line on the left-hand side.
set number
" Highlight cursor line underneath the cursor horizontally.
set cursorline
" Set tab width to 4 columns.
set tabstop=4
" Do not let cursor scroll below or above N number of lines when scrolling.
set scrolloff=10
" While searching though a file incrementally highlight matching characters as you type.
set incsearch
" Ignore capital letters during search.
set ignorecase
" Override the ignorecase option if searching for capital letters.
" This will allow you to search specifically for capital letters.
set smartcase
"show partial command you type in the last line of the screen.
set showcmd
" Show the mode you are on the last line.
set showmode
" Show matching words during a search.
set showmatch
" Use highlighting when doing a search.
"set hlsearch
" Set the commands to save in history default number is 20.
set history=100
" Enable auto completion menu after pressing TAB.
set wildmenu
" Make wildmenu behave like similar to Bash completion.
set wildmode=list:longest
" There are certain files that we would never want to edit with Vim.
" Wildmenu will ignore files with these extensions.
set wildignore=.docx,.jpg,.png,.gif,.pdf,.pyc,.exe,.flv,.img,.xlsx
"This unsets the 'last search pattern' register by hitting esc
nnoremap <silent> <Esc> :let @/=""<CR>
"Enable mouse
set mouse=a
" Fixes common backspace problems
set backspace=indent,eol,start
" Encoding
set encoding=utf-8
"for onedark
"Use 24-bit (true-color) mode in Vim/Neovim when outside tmux.
"If you're using tmux version 2.2 or later, you can remove the outermost $TMUX check and use tmux's 24-bit color support
"(see < http://sunaku.github.io/tmux-24bit-color.html#usage > for more information.)
if (empty($TMUX))
  if (has("nvim"))
    "For Neovim 0.1.3 and 0.1.4 < https://github.com/neovim/neovim/pull/2198 >
    let $NVIM_TUI_ENABLE_TRUE_COLOR=1
  endif
  "For Neovim > 0.1.5 and Vim > patch 7.4.1799 < https://github.com/vim/vim/commit/61be73bb0f965a895bfb064ea3e55476ac175162 >
  "Based on Vim patch 7.4.1770 (guicolors option) < https://github.com/vim/vim/commit/8a633e3427b47286869aa4b96f2bfc1fe65b25cd >
  " < https://github.com/neovim/neovim/wiki/Following-HEAD#20160511 >
  if (has("termguicolors"))
    set termguicolors
  endif
endif
set background=dark
colorscheme onedark
" Use a line cursor within insert mode and a block cursor everywhere else.
"
" Reference chart of values:
"   Ps = 0  -> blinking block.
"   Ps = 1  -> blinking block (default).
"   Ps = 2  -> steady block.
"   Ps = 3  -> blinking underline.
"   Ps = 4  -> steady underline.
"   Ps = 5  -> blinking bar (xterm).
"   Ps = 6  -> steady bar (xterm).
let &t_SI = "\e[6 q"
let &t_EI = "\e[2 q"
" }}}
" MAPPINGS --------------------------------------------------------------- {{{
" Mappings code goes here.
" }}}
" VIMSCRIPT -------------------------------------------------------------- {{{
" This will enable code folding.
" Use the marker method of folding.
augroup filetype_vim
    autocmd!
    autocmd FileType vim setlocal foldmethod=marker
augroup END
" More Vimscripts code goes here.
" }}}