Yes, I have seen this issue before. It can be frustrating when the arrow keys don't work as expected. The good news is that there is a simple solution to fix this problem.

Here are the steps to fix the arrow keys moving in the opposite direction:

1. Open Excel and click on the "File" tab in the top left corner.
2. Click on "Options" in the left-hand menu.
3. In the Excel Options dialog box, click on "Advanced" in the left-hand menu.
4. Scroll down to the "Editing options" section.
5. Uncheck the box next to "Enable fill handle and cell drag-and-drop".
6. Click "OK" to save the changes.

This should fix the issue with the arrow keys moving in the opposite direction. If you still have trouble, try restarting Excel or your computer.