Rails 4.2.6 fresh_when not functioning properly in passenger-standalone production

Rails
1

I’m trying to provide etag and last-modified headers for static page.
Locally it works fine and browser gets a 304, however on server with
passenger standalone it’s not providing a 304.

From http - Weak ETAGs in Rails? - Stack Overflow
it’s
clear that even if i give strong etag it’s getting converted to weak
etag,
the browser request response headers is listed in the following gist:
HTTP Cache · GitHub

The interesting fact is that the weak header is not even in the rails
request env. However if modify the etag from browser and send as strong
etag, it’s getting to rails env.
How can I resolve the issue so as to give a 304?

2

I got the issue. However the issue had nothing to do with passenger or
rails.
My ISP is using some **** proxy and was removing the If-None-Match
headers.
Tried another service and is working normally.