There are different versions of Excel, there's that cloud version which is a subscription-based purchase and there's the perpetual purchase which is a singular version.
The could version receives new features faster, this is because of safe deployment. I have seen instances of this where someone has the perpetual version installed (say from work) and then also purchased the family version. However, doesn't understand why there aren't any updates.
You were correct to reinstall and ensure you had the right version.
Next, I would ensure that all the updates are applied. This can be done through the Account menu item | Update Options | Update Now,
Does the problem exist if you open the spreadsheet in Excel online? excel.office.com, if it does do you have two versions installed? If you look in Add Remove Programs, do you have Excel installed twice (perhaps an older version and the latest version?) You might be opening the old version because it's associated with your xls files. If you do remove the old version.
Lastly you could try to do a repair, steps located here:
Here is the link about the detail steps of repairing an Office application: https://support.microsoft.com/en-us/office/repair-an-office-application-7821d4b6-7c1d-4205-aa0e-a6b40c5bb88b