Device Manager showing Gateway as "not SYNC"

Hi, I am new to this forum, sorry if I am not asking this question in the right place.

I have some IR300 routers deployed and working. But one of them lost access due to some unknown reason. Maybe the low battery level during some time put it in a bad state or something we don't understand yet.

However, the application that is running on that network is online and accessing the internet. I can see its logs remotely. 

Later, since the gateway was not accessible anymore through the Device Manager, my college removed it from there and tried to add it back. Now its status is "no SYNC".

Since this router was deployed, it is far away from us. We have its serial number. Is there any way to make it sync again remotely without local intervention?

Let me know if there is something that I could have tried or explained better.
Thanks, I appreciate any help.