After expand, mode change to normal. (from select pooups) about vim-vsnip HOT 4 CLOSED

scriptversion 4
call plug#begin()
Plug 'junegunn/vim-plug'
Plug 'prabirshrestha/asyncomplete.vim'
Plug 'prabirshrestha/asyncomplete-lsp.vim'
Plug 'prabirshrestha/vim-lsp'
Plug 'hrsh7th/vim-vsnip'
Plug 'hrsh7th/vim-vsnip-integ'
Plug 'rafamadriz/friendly-snippets'
call plug#end()
imap <expr> <C-j>   vsnip#expandable()  ? '<Plug>(vsnip-expand)'         : '<C-j>'
smap <expr> <C-j>   vsnip#expandable()  ? '<Plug>(vsnip-expand)'         : '<C-j>'
imap <expr> <C-l>   vsnip#available(1)  ? '<Plug>(vsnip-expand-or-jump)' : '<C-l>'
smap <expr> <C-l>   vsnip#available(1)  ? '<Plug>(vsnip-expand-or-jump)' : '<C-l>'
" map additional beginning
imap <expr> <C-y>   vsnip#available(1)  ? '<Plug>(vsnip-expand-or-jump)' : '<C-y>'
smap <expr> <C-y>   vsnip#available(1)  ? '<Plug>(vsnip-expand-or-jump)' : '<C-y>'
" map additional ending
set viminfo+=n~/.vim/viminfo
set background=dark
" The below setting has nothing to do with the issue.
" To make it easier to understand the mode in the video.
colorscheme desert
filetype plugin on
set laststatus=2
augroup InsertStatus
  autocmd!
  autocmd InsertEnter * highlight StatusLine ctermfg=red   guibg=red
  autocmd InsertLeave * highlight StatusLine ctermfg=white guibg=white
augroup END