Fixing Hyperlinks in a Copied Worksheet (on an Apple Mac)

May I answer your question with a question?

Why do you have a separate sheet for each month? 

Now, what lies behind that first and primary question is this: in general, unless there's some compelling reason, Excel can work far FAR! more efficiently with a single database of transactions, so long as those transactions are stored with date, amount, (and such subordinate headings as "source," "budget category 1,"  "budget category 2", etc.

A single database can serve as the source for a Pivot Table that breaks out and summarizes the details by month, by category. I've attached a very simple example. On a more personal basis, I have a far more extensive transactional database--holding transactions for multiple years, multiple bank and credit card accounts--and the Pivot Table is THE tool I use to summarize all of those at whatever level of detail I wish. The Pivot Table has been, since it first appeared on the spreadsheet scene at least 40 years ago (I can recall using that tool in the 1980s), one of the most powerful and popular reporting methods. Here is an excellent resource to learn more about Pivot Tables. YouTube also has a wealth of videos on the subject.

Nowadays, there are even more customizable ways to create dynamic summaries of transactional data--such as you have here--producing "dashboard summaries" by category, by month, etc. The Dynamic Array functions come to mind.

Bottom line: I highly recommend that you consider a total redesign. It will be easier to maintain, and far easier to extract meaningful summaries.