I have the following worksheet

in cell A19 - =A18
in cell A20 - =A19
in cell A21 - =A20
in cell A22 - =A21

if I insert a new row in between A19 and A20, I get

in cell A19 - =A18
in cell A20 -
in cell A21 - =A19
in cell A22 - =A21
in cell A23 - =A22

Previous Cell A20, which becomes A21 does not increment the cell reference to A20 - it stays at A19. The other cells increment the cell reference as expected.

How do I get the reference to update?

TIA
Dave