Conditional format formulas that contain any relative references are not
adjusted correctly for cell moves

eg
In cell A1 put =$A$2
Put conditional format on cell A1 formula is - "$A$2"

In cell A2 put TRUE/FALSE to show conditional format as set

Now insert a new row 2

The formula in A1 is now $A$3, and the conditional format formula has been
similarly adjusted as expected.

Now repeat the above using relative refences. The cell formula is updated but
the conditional formula is not.

Inserting a new row 1 does cause the conditional format to be updated,
presumably because the cell containing it does move.