I wouldn’t have thought a floor fan would interfere with a wireless transmission. But once I turned off the fan I stopped getting errors from the sensor.
However im not surprised it does interfere.
It depends on the design of the fan, but I’d expect most of them to have some form of electric motor in them. It’s quite possible for a motor with worn brushes to generate lots of very tiny sparks. Some of the earliest radio transmitters used spark gaps to generate signals, so you can see how it’s possible for a motor to act as a transmitter!