I have a question about the gateway JSON down message

I have a question about the gateway JSON down message.
In the JSON down message, freq is displayed as 921.9.
Why is this freq? Is it 921.9?
How do I change 921.9 to 914.9?
The JSON UP freq from the Lora Device is 914.9
The JSON down freq from Gateway to Device is 921.9.
Lora Device does not receive data sent by Gateway.

My gateway action message is as follows. :

JSON up: {“rxpk”: [{“tmst”: 1128657108, “chan”: 4, “rfch”: 0, “freq”: 914.900000, “stat” “,” Data “:” QHYTBCaAwSUCoOatoVEwiih0jZEppMeQ “}, {” tmst “: 1128657108)”: “SF10BW125”, “codr”: “4/5”, “lsnr”: 9.8, “rssi” , “chr”: 1, “rfch”: 0, “freq”: 914.900000, “stat”: 1, “modu”: “LORA”, “datr”: “SF10BW125” , “lsnr”: 9.5, “rssi”: -84, “size”: 24, “data”: “QHYTBCaAwSUCoOatoVEwiih0jZEppMeQ”
INFO: [up] PUSH_ACK received in 67 ms
INFO: [down] PULL_RESP received - token [198: 133] :slight_smile:

JSON down: {“txpk”: {“imme”: false, “tmst”: 1130657108, “freq”: 921.9, “rfch”: 0, “powe”: 23, : “Ncrc”: true, “data”: “YHYTBCaFAQADVX8AAQE8p25z4ArBUXECsi / 7”}, “id”: “SF12BW125”, “codr”: “4/5”
INFO: [down] PULL_ACK received in 69 ms
INFO: tx_start_delay = 1495 (1495.500000) - (1497, bw_delay = 1.500000, notch_delay = 0.000000)

The downlink frequency is determined by the TTN back end depending on the regional parameters for the region you configured in the console. You can not change or set it.