Simple formula not being interpreted

Hi!

I have an existing spreadsheet.
I inserted a new column with =len(g2) into it.

The cell correctly displayed 3 as the length of g2.

However, if I FILL the formula down the sheet the value remains at 3 all the way down.
If I go into the actual cell via F2 followed by return then all is okay.

However, I do not want to be forced to F2 over 10,000 cells.
I have tried different format for the column but to no avail.

Tools > Options > Calculation, Automatic

Thanks.

The F9 update had been turned off!