Ruby instance variables (starting with @) are highlighted in comments

[diegosomar]

When I comment some lines started with an instance variable, the color won't change to gray. See image below:

The file is *.rb

My env:

vim version: NVIM v0.5.0-619-g1153ac903
node version: v12.18.3
term: screen-256color
platform: linux (wsl2 in windows terminal with tmux)

Gruvbox vimrc

if !exists('g:syntax_on')
  syntax enable
endif

set termguicolors
let g:gruvbox_contrast_dark="hard"
let g:gruvbox_invert_selection=0
let g:gruvbox_italic=0
let g:gruvbox_italicize_comments=0
colorscheme gruvbox

My plugins:

call plug#begin('~/.vim/plugged')
Plug 'jiangmiao/auto-pairs'
Plug 'sheerun/vim-polyglot'
Plug 'neoclide/coc.nvim', {'branch': 'release'}
Plug 'preservim/nerdtree'
Plug 'rbgrouleff/bclose.vim'
Plug 'alvan/vim-closetag'
Plug 'tpope/vim-surround'
Plug 'tomtom/tcomment_vim'
Plug 'mileszs/ack.vim'
Plug 'morhetz/gruvbox'
Plug 'justinmk/vim-sneak'
Plug '2072/PHP-Indenting-for-VIm'
Plug 'nelstrom/vim-visual-star-search'
Plug 'vim-language-dept/css-syntax.vim'
call plug#end()

[uunnxx]

But, looks cool :)