In calc, for some reason I can't get formulae to work properlycalc

The formula works by itself in the normal manner, but I want to apply the same formula to later numbers going down the same column. This used to work beautifully, but now nothing appears after the first line. When I examine the 2nd, 3rd line, the formula is there and the references are correct, but no result. This is driving me mad as I’ve done this 100s of times before.

Please provide a sample file.

could someone add [solved - erratic question] or [solved - user error] or {solved - option not set] to the title?

Sorry I managed to resolve it myself. Discovered that autocalculate was not selected for some reason.
The matter is resolved.