Frequency offset for radio module

[zanco]

Testing a board with HPD14A V1.2 lora module (SX1278 433 - 470 MHz) I notice offset between set frequency and transmitted frequency for both RTTY and V2 4fsk and not for LoRa and APRS LoRa

For LoRa my receivers report average - 0.6 kHz offset.
For APRS LoRa my receiver reports -0.1 kHz offsett.

TX frequencies for RTTY and 4FSK are 6 kHz below the frequency set in the config. By adding 6 kHz to them I can get them on the wanted frequency. Difficult to test if this offset changes with frequency.

Any idea why lora TX is on frequency but RTTY and 4fsk are not ? Not sure if any other users experience the same.

Thanks,
Ben