Dragino LHT65N sending two uplinks at once

Hi Everyone.

I am using a Dragino LHT65N linked with my gateway Dragino LPS8N. The sensor was working fine as programmed (uplink interval 5 min) until recently when it strated to send another uplink 2 seconds after the first uplink (see below)

The frame count increments for every uplink and the uplink ID is different as well. However the data on the 2nd uplink is always the same (same timestamp form previous data and readings). This uplink also never gets acknowledged by the gateway.

I have tried to clear the buffer of the sensor, but the issue is permanent.
Does anyone have ever encountered this before and how could I get this data to be acknowledged or deleted once and for all?