thank you for your advice!
Opening a service request is still a viable option, and makes totally sense!
In posting my problem here I had the idea of getting quick advice like yours. Thanks again.
In fact I just saw ntp daemon is not running, although time is running correctly here, but you never know ...

I'm still looking into that problem, but it's confusing ... cause today all channels synced successfully ... whereas yesterday there were many errors ...
If those errors pop up again then I will open an SR!