I fixed this issue by adding the lines in wordpress default .htaccess file.
DirectoryIndex index.php
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /your-q2a-directory/
RewriteCond %{REQUEST_URI} ^(.*)//(.*)$
RewriteRule . %1/%2 [R=301,L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^.*$ /qa/index.php?qa-rewrite=$0&%{QUERY_STRING} [L]
</IfModule>
Note: change your-q2a-directory with your Q2A directory name