Dear Titanium5er,
Thank you for sharing this issue with the Microsoft community.
I understand that when you create a formula in Excel, it no longer works after 47 rows, I understand your frustration and will try to help you troubleshoot.
I tried to open the link you shared, which does have some errors in the formula after 47 rows, not displaying the corresponding values correctly. But I tried testing the formula in other cells and this seems to be working:

I would like to confirm some information with you in order to get a better picture of the status of the problem:
- Do you have any other formatting or rules set in the area where the formula is used?
- Can you recreate an Excel file and apply the formula? Troubleshooting to see if the current Excel file is corrupt.
I think the formulas you have entered in the document are correct and I suggest you try creating a new document to check.
I hope this gives you some advice on troubleshooting.
If you have any progress or other questions, feel free to contact us in the community.
Best regards
Isabella-MSFT | Microsoft Community Support Specialist