So when I am working on my menu or main nav everything I do lets say on home, does not alter what I did on my services page. They have the same class name and they still are not changing.
Any ideas
That is to broad of a question. It’s a feature designed to save you time. If you don’t use them when you have repeatable elements that could be better maintained with a symbol, then that would be a downside.
Note: You may need to create different copies for different sections of a site. Easy, drag to page, unlink from symbols, make edits, save as new symbol. Use where appropriate. Now you have two symbols to maintain, and so on.