Video Navigation no Longer Working

[tmwsiy]

When I use the pull-down menu to jump to a specific time, it seems like it is working: I see the spinning circle in the middle of the player window, but the video stays at the beginning.
The time counter to the left of the pull down indicates the time I attempt to start at, but just stays wherever it has been at the time.
I am trying vids that I know I have successfully advanced in the past.
I have tried clearing cache, rebooting, etc.

Any thoughts?

[GJ51]

In my experience this has been more to do with the encoding and indexing of the source video, especially with mp4's.

[tmwsiy]

In my experience this has been more to do with the encoding and indexing of the source video, especially with mp4's.

Not in this case. I have a few hundred videos and none of them work.
Never had an issue before with the same videos.