If you enable the first url structure and try to access to your website, which error do you receive ?
Do you see any message in your error_log ? ("Logs" section of CPanel)
However another quick (& dirty) check you could do (to check if the AllowOverride has been correctly set for your website) is reported here :
Invoke your websiteurl/index.php using this site
that allows you to see the response headers, and foow the instructions of the link that I've sent to you.
(The first test requires that you have the mod_headers enabled; if you do not have it installed you'll see an error on your error log file and you cannot do the first test; the second test is independent from the installed modules you have).
If the AllowOverrides works from the outcome of these tests, but on q2a the htaccess does not work, than probably your mod_rewrite has not been enabled (but you should see an error on your error log file; see at the beginning of my comment).
However you should wait for your hosting provider's answer to know exactly if the AllowOverride option is set AND the mod_rewrite has been enabled on your website.