KNX Dimmer with stange behavior (openhabian 1.4)

I have a DALI<–>KNX Gateway with a Meanwell LCM-60DA LED-Dimmer.
The corresponding Item:

Dimmer  Test_LED  "LED Dimmer  [%d %%]"  <hue>  (Testkram)  { knx="2/7/3, 2/7/3, 5.001:2/7/1" }

which is shown as a slider in the sitemap:

Slider  item=Test_LED

The first and the second Group address (2/7/3, 2/7/3) are dummy which don’t exist. I use them for debugging,
So I ensure nothing goes to the “Dimmer-Switch” and the “relative Dimming”. Only GA ( 5.001:2/7/1 ) is the one for the
Dimming-Value.
Appart from not showing the Value in Percent, the Dimmer ist working most of the time.
Events:

2018-01-27 16:59:08.321 [ome.event.ItemCommandEvent] - Item 'Test_LED' received command 58
2018-01-27 16:59:08.335 [vent.ItemStateChangedEvent] - Test_LED changed from 96 to 58

SO, I slide the slider, Item receives command, Light intensity changes.
But every now and then it happens:

2018-01-27 16:59:06.307 [ome.event.ItemCommandEvent] - Item 'Test_LED' received command 96
2018-01-27 16:59:06.329 [vent.ItemStateChangedEvent] - Test_LED changed from 12 to 96
2018-01-27 16:59:08.321 [ome.event.ItemCommandEvent] - Item 'Test_LED' received command 58
2018-01-27 16:59:08.335 [vent.ItemStateChangedEvent] - Test_LED changed from 96 to 58

And it is allways a “58” which is popping up. Then the intensity changes to 58. (which I don’t like it to do)

What am I doing wrong here???

sorry for posting, I think it is this topic: