How to prevent .htaccess file to be overwritten ?

Hello,

I have a WordPress site & in every 2-3 weeks It’s showing 500-Internal server Error. When I check Error logs, I notice .htaccess file is causing the issue. .htaccess file is automatically overwritten. After removing the old .htaccess file, the site works fine.

Can you please tell me why .htaccess is automatically overwriting & How Can I prevent this.

Currently my .httacces file is looking like this .

# 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

Thank you
Gyan