I tried to read a bit and understand the NTP synchronization implementation in FE computers. I'm quite sure that NTP synchronization should be 'yes' if timesyncd are running correctly in the output of timedatectl in these computers. As Koji reported in 15791, this is not the case. I logged into c1lsc, c1sus and c1ioo and saw that RTC has drifted from the software clocks too which does not happen if NTP synchronization was active. This would mean that almost certainly, if the computers are rebooted, the synchronization will be lost and the models will fail to come online.
My current findings are the following (this should be documented in wiki once we setup everything):
The solution to this issue could be as simple as just defining ntpserver in the name server list. But I'm not sure if my understanding of this issue is correct. Comments/suggestions are welcome for future steps.