Do you bake the macarons with fan on or off?

No fan. If you have a fan-assisted ("convection") oven turn it off.

The typical household oven in the USA does not have a fan so standard consumer-focused recipes quote temperatures for no fan.

Paul Hollywood (of the Great British Bake-Off) always quotes a 20 degree Celsius difference between fan and no fan. So this would be 160 °C (no fan) and 140 °C (fan). In Fahrenheit, this is a ~35 °F difference.

Remember that the notion of an accurate oven controlled by a thermostat is fairly recent in baking history. In the late 19th century, everyone was basically still throwing logs into a wood-burning oven; baking recipes from this era never had an exact temperature or time measurement.

Many consumer ovens perform differently so it looks you should rely on your own adjustments for future bakes should you follow American recipes.

Did you use the fan? Ovens can be finicky. It sounds like you’ve figured yours out.