Built in webserver "waiting for localhost"

If I click the chrome icon in the top left of an html (or php) file in my project, it spins forever "waiting for localhost" on a white screen.

I seem to have PHP installed and set up with IDEA correctly.

I have no servers set up in the Deployment page, as the help page on the built-in web server says they are something that can be used instead of the built-in.

Currently I have the IDEA server and the PHP server both set to the same port but previously I tried them with different ones.

Any ideas? Thank you!