Preview not matching the saved/exported file.

Parts that I've trimmed for my video look fine in the preview but when I save and watch the edited video the parts I had trimmed are still there. I came across another question with the same problem that didn't have a clear answer. From my provided video you can see in the finished product the title cards that were previously trimmed out are still there but in the preview they aren't. I had tried trimming my clips and it hasn't worked. I really don't want to redo my project.  I'd like to know if there's any solution to this, thank you.

This is the similar question.                                                                                    This is a video of my issue.