If a battery powered original redsetter behaves like this with only a short flash but no long flash, it is normally a sign that the battery should be replaced. I suggest to replace the battery to avoid chips being ruined by garbled data being written to them.
I have had a few chips go bad possibly caused by a redsetter running low on battery.
The PGI-520/CLI-521 redsetter uses around 5mA during a reset. To test the CR2032 cell in a realistic way with a simulated load the cell should be tested with a voltmeter in parallel with a resistor of 3.3/.005 = 660 Ohms. Use a standard 680 Ohm 1/4 W resistor.
The use of a high input impedance voltmeter without load resistor in parallel might lead to a false good indication. More about resetters and batteries
in this thread.