Hue Binding with HTTP Binding on Alexa dim Lights

The command will somehow not be forwarded to HTTP Binding to dim the lights.

My item:

Number Night_Light_Percent "Night Light"    <light> (GF_Living, Lights) ["TargetTemperature"] { http=">[*:POST:$s]" }

The Log:

2017-03-04 23:11:14.970 [ItemCommandEvent          ] - Item 'Night_Light_Percent' received command 8
2017-03-04 23:11:14.987 [ItemStateChangedEvent     ] - Night_Light_Percent changed from 20 to 8

Alexa is doing the job, OH2 also and set the percent but the Light has still the same brightness.

My other item is working great from App, Homekit and Web:

Dimmer Night_Light   "Night Light"    <light> (GF_Living, Lights)     ["Lighting"]    { http=">[*:GET:$s]" }