Reverse cache not working on start pages (solution founD)

[Dingo]

I found the solution, but I don't understand what it does. When I add:

proxy_cache_key "$host$uri$is_args$args";

To a location block it magically works. I have no clue what happens, it was
just a snippet I found on the Internet used by some other guy setting up a
reverse proxy with cache.

And thanks to Maxim and pbooth for trying to help me.

Posted at Nginx Forum: https://forum.nginx.org/read.php?2,276670,276833#msg-276833