Ctrl+Enter for Round2 formula

In my column B, there is some Cell with Fix Value, some with formula and the formula aint the same. I want to do Round2 for all. My B1 is a formula (eg C1+D1), hence i select the whole column B. Put the Round2 formula in B1, then CTRL Enter. Now all column B has Round2, however, i discover ALL formula become (C2+D2, C3+D3 etc etc.) Even my Fix value has formula now. How can i just add Round2 formula to all cell using the Ctrl Enter method Without amending the original content/formula of the cell???

Unfortunately I don't understand exactly what you are asking.

What result are you expecting? From your description CTRL-ENTER is behaving as it should.

Do you expect your C1+D1 formula to propagate only to empty cells in column-B?

Does "Round2" have some significance for us? If so then what does it mean?

Do you really want to propagate your formula to all million-plus rows of column-B?

With reference to the following image: if you put "=D1+E1" into cell B1 and then perform some operation (not CTRL-ENTER!) that achieves your expected result then what would you expect to see in each of the 10 cells B1:B10, given the starting point shown in the image.

ctrlEnter.png