It seems that when I was pausing with playableDirector.Stop(); and resuming with playableDirector.Start() the animation was not starting as it should. But i changed it to playableDirector.playableGraph.GetRootPlayable(0),SetSpeed(0) and now it seems to be working as expected.
About the other solution with "Don't end with clip" i don't think it will do the job.
For example let's check this timeline. Spine is on Track 1 and Track 3, these are 2 different characters. I would like to be able to start the timeline at different spots, not every time at 0. So currently when i go to the position where the pointer is on the image for example there is no clip for the second player because it comes later, so I would like there to be an Idle animation for example. That's what I am trying to achieve, i guess an option is to fill all the empty spaces with Idle clips and when the character dies with death clips but not sure if that is the best solution. Also i should mention that I am creating the whole timeline trough code.