Why is the monitors reseting to zero after key is turned off? on 1997 Honda Civic

Replaced O2 sensor and air filter box. Re- smoged car after repairs-passed. Customer took to Test only station
failed three incomplete moitors. O2 Cat. and Evap. When I
tested monitors passed. Cust took to T.O. Station turned car off then failed on monitors. Why?

Asked by for the 1997 Honda Civic