Tomcat 404 error after swapped META-INF/context.xml file

Question

I have Tomcat 8 installed on CentOS 7 x64

I had it set up correctly so I could go to Tomcat's manager app. I then swapped /META-INF/context.xml to a different context.xml file. After changing the context.xml file I got a "404".

The problem is that after changing the context.xml back to the original shape I am still getting the "404" (even though the only thing that had changed was the context.xml file and this file was now back in the original state).

I have tried restart tomcat, reboot server,...

The logs aren't showing any errors and catalina.out is showing that the manager app is being deployed when tomcat is starting.

My question is this, what part of tomcat is storing this broken state? I would have thought that going back to the original, working context.xml would make my tomcat work again, so what could that file have changed about tomcat that is being persisted even after restarting tomcat?