I renamed .htaccess to enable and disable it several times, and each time I enabled it PHP started showing blank white pages for everything, and when I disabled the .htaccess file PHP files would start working again. I didn't bother to look inside the .htaccess file because I try to focus on providing support for our servers, not support for code issues. I came to the conclusion that it was a code issue, not a server issue, so I marked this topic as solved. Not sure why the issue started in the first place. We definitely didn't mess with your files so either
You edited it.
The software itself caused the issue due to some bug.
Some third party got access.