Changing LoRa parameters - Is necessary to restart device?

[lsoria]

Hi all,
I'm working with lopy4 in raw LoRa mode. I've implemented methods to change the radio settings (SF, CR, BW, among others) and store the configuration in a JSON file. The fact is that those changes are not visible after I reset both node and gateway (My code is based on LoRa-MAC Nano-Gateway). Is that correct? invoking the method lora.sf([sf]) for example does not make any changes.
Here is my method implementation:

    def changeLoraSettings(self, lora_conf):
        # print('Changing LoRa configuration...')
        [lora_bw, lora_cr] = self.parseData(lora_conf)
        self.lora.frequency(lora_conf['frequency'])
        self.lora.tx_power(lora_conf['tx_power'])
        self.lora.bandwidth(lora_bw)
        self.lora.sf(lora_conf['sf'])
        self.lora.preamble(lora_conf['preamble'])
        self.lora.coding_rate(lora_cr)
        # print('done')

     def parseData(self, lora_conf):
        if(lora_conf['bandwidth'] == '125 KHZ'):
            lora_bw = LoRa.BW_125KHZ
        elif(lora_conf['bandwidth'] == '250 KHZ'):
            lora_bw = LoRa.BW_250KHZ
        elif(lora_conf['bandwidth'] == '500 KHZ'):
            lora_bw = LoRa.BW_500KHZ

        if(lora_conf['coding_rate'] == '4/5'):
            lora_cr = LoRa.CODING_4_5
        if(lora_conf['coding_rate'] == '4/6'):
            lora_cr = LoRa.CODING_4_6
        if(lora_conf['coding_rate'] == '4/7'):
            lora_cr = LoRa.CODING_4_7
        if(lora_conf['coding_rate'] == '4/8'):
            lora_cr = LoRa.CODING_4_8
            
        return [lora_bw, lora_cr]

lora_conf is a dictionary which is stored as a JSON file:

def lora_default_config():
    lora_conf = {}
    lora_conf['region'] = 'AU915'
    lora_conf['frequency'] = 915000000
    lora_conf['tx_power'] = 20
    lora_conf['bandwidth'] = '125 KHZ'
    lora_conf['sf'] = 7
    lora_conf['preamble'] = 8
    lora_conf['coding_rate'] = '4/5'
    lora_conf_encoded = ujson.dumps(lora_conf)
    with open("/flash/lora.json", 'w') as conf_file:
        conf_file.write(lora_conf_encoded)
        conf_file.close()

I will provide any other information you shall need. Thanks in advance!