.htaccess redirect not working for mobile browser

# BEGIN Redirecting from www to non-www site
RewriteEngine on
    RewriteCond %{HTTP_HOST} ^www.teachmecool.com$
    RewriteRule ^/?$ "http://teachmecool.com/" [R=301,L]
# END Redirecting from www to non-www site

I am using the above code for redirection from www to non-www site. This code works fine in pc, but when I browse using mobile, its not working resulting in ‘This webpage not available’.

Any help is appreciated