1. go to https://www.reddit.com and view the front page
  2. ignore my computer for an extended period of time
  3. go back to my browser
  4. open a new tab
  5. go https://www.reddit.com
  6. click a link
  7. hit the BACK button

  8. Click REFRESH on stale https://www.reddit.com page
  9. Click link
 10. Click BACK

I am on the latest version of FireFox Quantum 57.0.1. Since updating to quantum, I've noticed a problem with the cache resolution when using the back button. EXAMPLE STEPS TO PRODUCE THE PROBLEM: 1. go to https://www.reddit.com and view the front page 2. ignore my computer for an extended period of time 3. go back to my browser 4. open a new tab 5. go https://www.reddit.com 6. click a link 7. hit the BACK button After step 7, I will see the reddit home page that I saw in step 1, not step 5. This issue is not in any way related with reddit specifically, its just an easy example to test against, since the content of the reddit home page changes frequently. Ultimately, it seems like something somewhere is retrieving old/stale cache when hitting the BACK button in certain scenarios; or perhaps the problem is that the cache isn't being properly updated in step 5. Continuing from the steps above, if I then do: 8. Click REFRESH on stale https://www.reddit.com page 9. Click link 10. Click BACK I do see the proper cached content (from step 8, not step 1). So, it's easy enough to work around, but it is kind of annoying.