Slider and sequencer

Hello everyone, I need your extensive knowledge, I have here on my project a slider allowing me to control my sequencer, so far so good, and I am currently trying to get my slider to follow the progress of my sequencer, it is now animated but when I want to check the progress again by moving the slider manually, the cutscene restarts and my slider no longer moves, I must have missed something, any ideas?
thanks in advance

Update,

I still have one thing to adjust, when I touch the slider with my mouse, and when I release, it stops following the progress of the sequencer, even if I restart the sequencer from the beginning, it no longer works