30 minutes delay between LMIC_setTxData2 and actual send

[i-g-g-y]

Hello.

There is a serious bug in the timing of the library.

I keep track of time and send out a packet every 2 hours with;

`
// Check if there is not a current TX/RX job running
if (LMIC.opmode & OP_TXRXPEND) {
Serial.println(F("OP_TXRXPEND, not sending"));
} else {
// Prepare upstream data transmission at the next possible time.
last_tx_time = millis();
Serial.print("\r\nTx req.");
os_setTimedCallback(&sendjob, os_getTime()+ms2osticks(100), do_send);

      LMIC_setTxData2(1, txBuffer, sizeof(txBuffer)-1, 0);

      Serial.println(F("Packet queued!"));
  }

`
Most times it works flawlessly, but sometimes I get 30 minutes of delay between queuing the packet and the actual send. Why is that?

I am using nRF52840.