Spacelynk Cpu load high

[domotiqa]

Start with disconnecting client devices and checking KNX/IP bus load.

knx bus load is 10% average. Never above 20% (except when programming with ets).
I disconnect the Touch screen HP slate 21 (android), same cpuload that increase from 0.3 at boot to 1 after 5 minutes.

Ask my self about hardware issue or something else !

I did factory restore from web interface. Should I do something else ?

PS: For info, I know there is 2 knx Ip device on the same network (2 other line as backbone router). I tried to disable Ip stuff from Spacelynk without any difference