I believe this is a bug on YouTube itself, not anything to do with Firefox. This happens sometimes to me on Firefox and I also have a friend who exclusively uses Google Chrome and says they have the same issue.

For me, I've noticed it only really happens when I close the tab entirely while the video is still playing. If I click the YouTube logo at the top first and then close the tab, it seems to usually save my video position for me.

It's appears to be something with YouTube not correctly detecting when you close the tab or YouTube not automatically updating the timestamp frequently enough in their system.

Either way, I'm not sure that it's Firefox-specific and I don't believe that there's anything we can do to help with this one.

This is an issue that doesn't happen for me in any browsers except firefox. in Opera it works fine same for google chrome it is just firefox.

Unless your login into your account YT will not keep a history of your playlist to replay from the last point it was stopped. What your describing is a non-registered YT account and as such that keeps no record of what was played to be replay from last stopped action. And if a YT account then your settings is not set to keep a record of playback to replay from when they were stopped the last time.

1. I am logged in to my youtube account 2. youtube remembers where i was in videos except when i use firefox for some reason.