Sometime, disconnect between Esp32 and gateway by use LMIC.h

[LoRaTracker]

@saratwadee

// Schedule TX every this many seconds (might become longer due to duty
// cycle limitations).
const unsigned TX_INTERVAL = 10

Welcome to TTN.

? your sending from the node every 10 seconds?

Are you aware of the fair use policy ?

Fair Use Policy explained

For The Things Network’s public community network the Fair Access Policy limits the data each end-device can send, by allowing: An average of 30 seconds uplink time on air, per 24 hours, per device. At most 10 downlink messages per 24 hours, including the ACKs for confirmed uplinks. A good goal is to keep the application payload under 12 bytes, and the interval between messages at least several minutes. An online airtime calculator can give you some insight. The following regulations apply a…

Set the time to something like 600 seconds perhaps, and see if you have the same problem ?