Status gateway problem and no data

Hello,
I’m having trouble with my two gateways, a rasberry pi and a Kerlink.
Both were working fine, it had been running for 1 to 2 weeks, and since this weekend, my gateways have gone offline and don’t upload any more data, even though they are still connected to the internet and accessible.
I tried to restart them, they worked again, but only for a few hours before going offline and no more data.
I don’t know where the problem can come from, if someone could help me?

Thanks

Check the gateway logs and see if they are getting “ACK” responses to their “PUSH” and “PULL” operations.

eg

INFO: [up] PUSH_ACK received in 40 ms

Also look for the percentages in the periodic stats summary:

PUSH_DATA acknowledged: 100.00%

and

PULL_DATA sent: 6 (100.00% acknowledged)