WP Super Cache not working (even though test works fine)

Test Cache works fine.

But every time I load a page, and the timing at the end of source always shows that page has been created just now.
view-source:https://propstory.com/home/bangalore-real-estate/godrej-united/
<!– Dynamic page generated in 3.057 seconds. –>
<!– Cached page generated by WP-Super-Cache on 2017-05-22 17:55:11 –>

This time remains same only in case of same browser being used. If I open it in incognito or in other browser or on another machine, it will show latest time and not the older one when cache was generated.

I opened it after two minutes in different browser and it shows:
<!– Dynamic page generated in 2.127 seconds. –>
<!– Cached page generated by WP-Super-Cache on 2017-05-22 17:57:23 –>

Here are important settings for WP Super Cache:
Caching: On
Use PHP to serve cache files
Compress pages so they’re served more quickly to visitors. (Recommended)

Refresh preloaded cache files every 40080 minutes. (0 to disable, minimum 720 minutes.)
Preload all posts.

Any help would greatly be appreciated.