I read all the information from the link above.
The problem is that I come to the file selection step, I get the message "Image Uploading" and a spinning circle. After a few minutes, I lose connection with the device, I cannot get to the software verification stage.
The cellular network connection seems to be stable.
Downloading the firmware from the server is also not possible because the modem works in a private APN without access to the Internet. By the way, it would be good to add the option to select your own server for firmware update.
I will add that I am using an https connection.
