Time Remap filters is hard to work with, read the documentation
Ex.
having a 10s (30fps = 300 frames) clip and using at time remap filter and change the speed to 5x, the effective speed will be 150fps and you will run out of frames efter 2s, but the clip will still play for 10s. so you get 8s with no moving frames.
It can be easier to split the clip in multiple sections and use the properties to change the speed, because it wil change the lenght of the clip.