Excel Autocomplete is not working

I have Microsoft 365 Version 2512: January 13, (which I have checked is the latest update)

I am operating Windows 11 Home Version 25H2 (which is also the latest)

When I try to use the autocomplete facility in Excel it does not work, it just enters the first letter.

In File; Options; Advanced, the 'Enable autocomplete for cell values' tick box & the one below are both ticked.

I have tried this in all my existing worksheets and IMPORTANTLY in a new blank worksheet, which is what this is. I have just purchased this new laptop & loaded MS 365 in the last 2 months.

I have asked a friend to try it on his Windows 11 laptop with the Excel and his does not work on his either.

HOWEVER, it does work on my MacBook which is operating system Monterey Ver 12.7.6 & Excel Version16.89, which is an older version. This where I was previously using Excel.

There it works on excel spreadsheets, in a new blank worksheet AND also if I copy a relevant file and paste into the Apple iOS system it also works. So it appears that it does not work in Excel & Windows 11 (ref my friend's confirmation)

I have posted questions on Q&A but have not had any response that gives a valid reason for the problem or more importantly how to solve it.

I would obviously like to speak to someone about this, but I think this is likely to be impossible.

It appears that autocomplete does not function in Excel in Windows 11 which does not seem right.

Can someone help?