As member mwb1100 suggests:
whenever the scope goes from a disconnected to connected state (whether LAN or Wifi), it should automatically Sync NTP if "Power On Sync" or "Periodic Sync" is on
Is proposed for Siglent to consider.
I'm not against it.
But it is not a bug. No NTP service does that. I'm not even defending Siglent scope here. It's just no NTP is supposed to do that. On any device.
It is not a bug.
NTP does not care about network. After initial synch (on boot) because it has not battery backed up clock, next refresh is when built in software clock accuracy is questionable because it has been running too long, and then we recheck with NTP server if there are corrections needed.
Actually, if device clock is any good, it is recommended not to synch NTP too often, because it introduces timing jitter...
Updates are not correlated to network config, but only to clock needs..
If you boot with network connected it will work normally. If you boot with network not connected, it will timeout on initial synch. Until next scheduled update, when it will update if network was connected in meantime. Were you can use manual update to speed up things.
If you need reliable NTP, provide reliable network.
There is no built in "option to enable" or "bug to fix".
What can be done is to make separate monitor service that will be aware that time is not set (NTP client connect failed, or synch failed), and would keep that status and be mindful of network connectivity.
But you can have Ethernet port or WIFI connection UP and still have no connectivity to Internet.
What to do then? How do we detect NTP servers are available for synch then?
Gets complicated quickly...
What I think could be useful would be a marker (clock background painted red or something) to user that NTP is set to synch and failed last time. So they know they have network problems and that clock might be in in "uncal" state of a sort..