Non-anchored hyper links

OK - I have a large movie collection and keep track of it using Excel. The spreadsheet (created around 2005) currently has 30,000 rows and 10 columns with the first column being the movie title. When adding new entries do it two ways: A) Type or cut/paste the information at the bottom of the list B) Insert a row below and copy the above data into the new row (e.g. adding a Blu Ray with DVD already in spreadsheet). Every so often I do a sort according to Column A. About 6 years ago I decided to start adding a hyperlink from the movie title cell to the relevant IMDB address. This has resulted in some titles with and some without hyperlinks.
Several years ago I noticed that some cells in column A had hyperlinks however they were not showing the hyperlink blue with underline and the hyperlink was for a different title anyway. I also have discovered instances of a cell having no hyperlink yet showing blue with underline. These instances are now scattered throughout the spreadsheet. I remove incorrect hyperlinks as I find them. It seems like when I add a row the cells shift down but the hyperlink stays and attaches to a new cell but without the hyperlink colours.
I tried googling this problem but came across 100s of entries on "How to add hyperlinks" etc. so thought it would be quicker asking some pros. Thanks.