mod_rewrite(.htaccess)具有“.profile”文本的URL的奇怪行为

I got a hosting with WordPress engine installed and inside the root of WP engine folders I've created another web application which is having problems with URLs containing .profile word. When this text is added to URL I'm always receiving 404 error.
Here's an example:
WordPress blog URL: https://mainsite.com
Sub web application folder name: webapp
Sub web application access URL: https://mainsite.com/webapp/
So, when I try to access URL like this: https://mainsite.com/webapp/login.php?code=user.profile I'm receiving error 404. At the same time URL like this: https://mainsite.com/webapp/login.php?code=user.profilb is working fine (2nd URL got last letter replaced by another symbol).
I think this is an issue with WordPress default mod_rewrite settings, here they are:

# BEGIN WordPress
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>

# END WordPress

I got no clue at all why this could happen with .htaccess file like this. Could you suggest please?

It turned out that the issue was with mod_security of a2hosting. They were blocking all sensitive linux files and folders, like: .profile, .htaccess, .bashrc...
Hope, this will help someone.