Dec 27 2021 01:35 PM
What happens if you select Freeze Panes > Freeze Freeze Top Row on the View tab of the ribbon?
Dec 27 2021 10:40 PM
Here is a sample workbook with the top row of the worksheet frozen.
Is it frozen for you?
Can you unfreeze it? (Freeze Panes > Unfreeze Panes)
Can you then freeze the top row?
Dec 28 2021 04:54 AM
You might repair your Office installation to see if that solves the problem.