how downgrade? or a factory reset is possible?

i have an issue on an other topic (briefly: the green light is always activated if the Sensors & Accessories > Wrist Heart Rate is set to auto even if the battery saver mode is activated and the Power Manager > Battery Saver > Edit > wrist heart rate parameter set to off )

since it's a software issue, i wanted to do a factory reset and see if the 1st software of the watch has the bug or not.

in the watch there is a reset function, i tryed it but it keeps the last installed firmware. so is it possible to do a factory reset?

thanks