Slower data range will let you reach higher distance but higher air-time. High air-time means it will take awhile before you can transmit again to follow the US915 dwell time restriction.
What do you mean that doesn’t work? I saw that the lora:status already sent you the proper reply.
I gave up the configuration with the serial port, now I am going to try to directly modify the firmware with the RUI V2.0. I didn’t find a lot of ressources and documentation on the code of each module, do you know if there is explanation somewhere on it ? Or people who have created projects by this way ?