Hello ahovy,
Thank you for your post.
If you have the file of .avi format then you could try to enable "Obey sample times" setting in "Control / Obey sample times".
If you have this issue with another file format, could you please share this file with us - you could upload it to e.g. Google drive or Dropbox.com. Also please send the project file. To get it select the fragments for saving then follow File / Save project as.
Thank you in advance.