Problems
I used Automatic Proxy Configuration a lots when working. But I found that it is very annoying that the URL disappear if you untick the box of the protocol of the proxy configuration. This behaviour doesn't acts the same as other protocol to configure, like Web Proxy and Secure Web Proxy. I would like to ask whether it is a bug or it is by design.
Reproduce
Go to Network -> Advanced -> Proxies
Tick the Automatic Proxy Configuration with a good URL for the Proxy Configuration File
Click OK and then Apply in the Network page
The Proxy works and after the usage, go back to the same page
Untick the Automatic Proxy Configuration and click OK and Apply
Go back to the Proxies page
(Problem) the URL of Proxy Configuration File disappear
