I noticed that about one out of every 5 times I loaded a page, my nav bar would or would not be centered. I changed a million css properties trying to fix it, then I noticed the error_log kept updating.
First I was getting: PHP Fatal error: Call to undefined function get_header()
Every forum topic I read said that it had something to do with a corrupt install of wordpress. So, I did what people said. Deleted everything, put in a fresh install, then uploaded my wp-config and my theme. Still the same problem.
So, then I thought, hey! Why not just get rid of get_header!
then I removed all instances of get_header()
the bumping nav still happened and then it was PHP Fatal error: Call to undefined function language_attributes()
after deleting that I got PHP Fatal error: Call to undefined function bloginfo()
obviously I can't remove EVERY wordpress function from my wordpress install. And I've re-installed wordpress like twice!
Also, I've deactivated all my plugins and get the same result.