FF 74.0.1 returns cached webpage, even though cache-control & expires headers exist (and the page has expired).
I'm 99% sure this just started after my browser updated to 74.0.1 recently. I started noticing some pages going stale and had to shift-refresh them. Watching the developer panel FF was displaying a cached version of the page without making a request to the remote server. This is fine and all, EXCEPT the time had passed beyond what the cache-control 'max-age' & expires headers were set to, and the cache-control header included 'must-revalidate'.
These pages weren't just clicking back/forth either, they stayed stale even after clicking links to said pages.