Your text is ambiguous. Did you install the argon1.sh script or not? The argon1.sh script (or an alternative service/add-on) is required, even if the jumper is set to 1-2, to turn on the fan at high temperatures. It appears necessary to execute an I2C command at least once after booting to stop the fan when the jumper is set to 2-3.
I haven’t checked it with a recent script version, but if you are affected by the script issue, you can find a recent discussion and solution here: Argon ONE V2 - Fan always on after reinstalling RPi OS