A family of Microsoft spreadsheet software with tools for analyzing, charting, and communicating data.
You are confusing the operation of the Office Clipboard with the operation of Excel's CutCopyPaste mode.
When you copy/cut cells in Excel, you go into CutCopyPaste mode and must paste what you have copied/cut before you can continue working. If you do start working, you will exit CutCopyPaste mode and not be able to paste any more.
The exception to this is that when you are using the Office clipboard, and you copy/cut some cells, they are copied/cut to the Excel clipboard (same rules apply as mentioned before) as well as to the Office clipboard (separate memory store, different rules). You can paste anything from the office clipboard whenever you want (almost, as you have seen!).
So.
Press Esc. so that you are no longer using the Excel clipboard (dashed lines will disappear). Go to B27. click on the Notepad formula in the Office clipboard to paste it.