The goal here is to get a template page which will be duplicated and renamed, and still have all of its charts ready and working without changing any data settings. However, when I create new copies, the copied charts continue reading data from the original sheet.

I've tried my best to use the INDIRECT function to work around this, but Excel seems determined to input the name of the current sheet in next to it, which causes an error.

Does anyone else have any ideas on how to make my copied charts dependant on only their current sheet?

Fixed it. I was unaware that sheets could be copied using a method that wasn't Ctrl-A, Ctrl-C. Copying the sheets correctly (right clicking the sheet, and selecting "Move or Copy") fixed this issue.