Copying conditional formatting down a column in excel and the reference cell does not change

Question

When I attempt copy a set of formatting rules established for Cell F48, down a column the reference cell does not change.

In this example the rules created apply to Cell F48 as being equal to 0, less than or greater than Cell G48.

When I copy with format painter from Cell F48 down the column from F49 through to F100 the Rule keeps the Cell Value as being equal to 0, less than or greater than Cell G48 and does not change to reflect the Cells F49, F50, F51 etc. etc as I expected.

I am guessing it is something basic that I am doing wrong but hope someone can assist