Current time indicator keeps looping after a few seconds

Hi, I'm a beginner After Effects editor who just switched over from Davinci Resolve. I have encountered this problem recently where for some reason the current time indicator (the red line) stops a few seconds after the video starts playing and then continues to play in a loop from the start. It plays for about 2 seconds before looping again.  I am not sure how to fix this problem as I have tried to purge all memory and disk cache and I have also played around with the preview settings in the preview panel. An example is attached.