KNX dimmer problems with Openhab 2.4

Hello everybody

I’m a newcomer with Openhab, did first installation few months ago, now I’m running version 2.4. So far I’ve done just basic KNX configuration, mainly lighting and heating.

Now i got stuck with KNX dimmer, i can normally switch dimmable lights on and off, but dimming is not working. I can see on Zennio’s touch panel that command is send to KNX bus because dimmer percentage changes when I try dimm light with OH.

I’ve read documentation, community posts, but no solution yet. Could you please help me?

Channel configuration is as follows

and .item

Dimmer Light_Diningroom_Spot_307    "Ruokailutila testi [%d %%]"        <slider>        (Dim, LivingDining) {channel="knx:device:932f15e3:307"}

Thank you already for your help
rgds Jukka

Anybody ideas what might cause this malfunction or what should i check for errors?