eWon went offline due to change in date&time setting?



Hello team,
I’m fairly new to eWon, please bare with me if I wrote something stupid.
A little background: the site had an eWon Cosy 141, firmware 13.2 that has been online for a year. Last month, I added email feature for some alarms through eCatcher. Things worked well until last week, when customer reported that email being sent out with no corresponding to alarm’s state.
I figured out: along with correct emails, it also sent out emails with exact same timestamp of 3 weeks old frequently. Could it be a buffer error?
I browsed around the setting, and enable NTP time server. It ran for another 1 hour then went offline.
Now my questions are: Can I make it go online remotely? What could be the cause of same email being sent issue?
Thank you in advance for reading my post, any help is very much appreciated.