Custom theme files are being deleted from server

One of my clients is running a WordPress site on Cherry Framework and a purchased theme. I built a new template for landing pages. I have a page template files and custom headers and footers. Cherry is the main theme and the purchased theme is the child theme.

On three different occasions in the last month, my custom .php files have been removed from the theme folder. The files are literally removed. Other customizations that I have made to the css files in the theme are still there.

Any ideas what might have the power to remove files from the server? Plugins installed include the cherry plugin, conatct form 7 and w3 total cache. The site is hosted on bluehost.

Any advice would be appreciated.