I'm using a proxy script to connect to the Internet. I've set it, system wide, in :
System preferences -> Network -> Advanced... ->Proxies -> Automatic Proxy Configuration
and it works well.
I've also set it in Firefox
Preferences... -> Advanced -> Network -> Connection -> Settings -> Automatic Proxy Configuration URL
and it works well too.
In Safari, which use the system proxy configuration everything works well.
BUT in chrome Version 54.0.2840.87 (64-bit), which should use also the system proxy configuration everything is very slow and I always see, in the status bar, the message :
Resolving host in proxy script...
I've found the following thread about Proxy Pac and Sierra but it doesn't help.
P.S. I'm using macOS 10.12.1