I have three web servers running identical code. On main, one failover and one development server. Let's call them server1, server2 and server3.
If I load a page from server1, then view the source, the browser reloads the source from the server.
If I load the same page from server2 or server3 they both show the page source without reloading. This is true for both Chromium and Firefox.
The servers are running the same php scripts. They have AFAIK identical nginx/php-fpm installations.
It must be server-side issue because I am using the same browsers in all cases, just changing the IP of the domain from one physical server to another.
What directive could the server be sending to the browser to tell it not to reload? Not an HTTP directive, because there is no difference in the php code from one server to another. I am thinking something at the web server level?
If I reload the page it actually reloads. Only View Source avoids reloading on server2 and server3, which is the behaviour I want. server1 is the one I want to force the browser not to reload on View Source
Edit: I don't believe it is a duplicate because the above question is written by a newbie wanting to know why they can't execute a php script on the client side. The question I have is why does an identical page get reloaded on View Source when it is served by one server but not get reloaded when it is served by a different server? Same browser. Page served by same php code on both servers.
Edit: As to the second "duplicate", thank you for pointing out the post on Firefox. I did read this post when I began researching but the problem affects Chromium as well.