Power = Torque * rotational speed
Torque = Force (what the power meter measures) * distance (crank length)
Power = Pedal force * crank length * rotational speed
So since you lied to the power meter and told it to use a longer crank length than actual in the power equation, it was inflating your power numbers (reading higher than reality).
One important caveat: Assiomas use the crank length set in the recording device (Garmin, Trainer Road, etc) as the crank length. Whatever you set in the Assioma app will be ignored on other devices / apps. So you need to check what you had set in the devices and apps you use to record with to see what crank length you were actually using. Maybe you’ve been using whatever default was set there?