Motor kicks out at just over 18mph

[heatlamp]

On my 2018 Arroyo the motor starts kicking out at something like 18.2 mph, completely gone by 18.5 or 18.6 (at least according to the power bar on the speedo). Annoying. Anyone seen this? Anyone know if this is fixable?

Tx

 

[Steve-H]

My 2019 Arroyo and 2020 Ultimate T10 both seem to first of all read low relative to radar speed displays that I trigger and casual comparison to iPhone gps speed. So if I go by the radar with 30 kph showing on the Purion display, the radar display is 2 kph lower at 28kph. The limit of ebike law is 20mph or 32km/h. So I get the motor boost tapering off from 30km/h until it does not boost at 32km/h and above. This is the designed behaviour: to taper boost. But the reading is not true so I believe the factory setting is 2km/h too low relative to the allowed max by law.
I did take the Arroyo to the dealer to check and they did move some slider in the motor somewhere. What happened is that my Purion display now agrees with the radar, but the tapering now seems to start at 28km/h and is off at 30km/h. So I have a readout of less speed but agrees with the radar. No actual performance change.