Maybe have a look here KNX - States change after some time even if they are correctly set - #15 by pridi
There is even a link to the knxa article, but it seems broken now 
Nevertheless you’ll find a couple of similar threads here.
Maybe have a look here KNX - States change after some time even if they are correctly set - #15 by pridi
There is even a link to the knxa article, but it seems broken now
Nevertheless you’ll find a couple of similar threads here.