.htaccess disappears every few minutes

i have a strange problem. The .htaccess file on my FTP disappears every few mins, and im being have to put it back from my backup to make my web pages work again.

(No its not hiding it. i enables showing hidden files. And when it disappears my website pages wont work.)

So i am putting it back every few mins to keep my web site up and running. i thought it may be connected to ithemes security.

can anybody help me?

https://www.ads-software.com/plugins/better-wp-security/