Hi @jaski.tx
Please find my dmesg log in the attachement: dmesg log
In the meantime I disabled ntp (timedatectl set-ntp false) and set the RTC as localtime (timedatectl set-local-rtc true). And before I launch my application I exectued hwclock -s. This seems to work as the systemclock is overwritten from the RTC now. However shortly thereafter and automatic ntp sync seems to take place although it is disabled. Do I need to disable it somewhere else?